development of pipe welding, cutting & inspection …
TRANSCRIPT
JAERI-Tech99-048
JP9950431
DEVELOPMENT OF PIPE WELDING, CUTTING& INSPECTION TOOLS FOR THE ITER BLANKET
KiyoshiOKA, Akira ITO, Kou TAGUCHI, Yuji TAKIGUCHI,Hiroyuki TAKAHASHI and Eisuke TADA
Japan Atomic Energy Research Institute
, Xw^tjWffitft&uffiftfflu (1=319-1195
(=r319-1195
This report is issued irregularly.Inquiries about availability of the reports should be addressed to Research
Information Division, Department of Intellectual Resources, Japan Atomic EnergyResearch Institute, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan.
© Japan Atomic Energy Research Institute, 1999
JAERI-Tech 99-048
Development of Pipe Welding, Cutting & Inspection Tools for the ITER Blanket
Kiyoshi OKA, Akira ITO, Kou TAGUCHI, Yuji TAKIGUCHI, Hiroyuki TAKAHASHI and
Eisuke TADA
Department of Fusion Engineering Research
(Tokai Site)
Naka Fusion Research Establishment
Japan Atomic Energy Research Institute
Tokai-mura, Naka-gun, Ibaraki-ken
(Received May 25, 1999)
In D-T burning reactors such as International Thermonuclear Experimental Reactor (ITER),
an internal access welding/cutting of blanket cooling pipe with bend sections is inevitably required
because of spatial constraint due to nuclear shield and available port opening space. For this
purpose, internal access pipe welding/cutting/inspection tools for manifolds and branch pipes are
being developed according to the agreement of the ITER R&D task (T329). A design concept of
welding/cutting processing head with a flexible optical fiber has been developed and the basic
feasibility studies on welding, cutting and rewelding are performed using stainless steel plate
(SS316L). In the same way, a design concept of inspection head with a non-destructive inspection
probe (including a leak-testing probe) has been developed and the basic characteristic tests are
performed using welded stainless steel pipes. In this report, the details of welding/ cutting/
inspection heads for manifolds and branch pipes are described, together with the basic experiment
results relating to the welding/cutting and inspection. In addition, details of a composite type
optical fiber, which can transmit both the high-power YAG laser and visible rays, is described.
Keywords : ITER, In-pipe Access Tools, Blanket Cooling Pipe Maintenance, YAG Laser,
Welding and Cutting, Non-destructive Inspection, Leak Test, Composite Fiber
This work is conducted as a ITER Technology R&D and this report corresponds to ITER R&D
Task Agreement (T329).
JAERI-Tech 99-048
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JAERI-Tech 99-048
Contents
1. Introduction 1
1-1. Task Objective 1
1-2. Scope of the Report 1
2. Design Concept for the Blanket Maintenance 3
2-1. Design Conditions 3
2-2. Design Concept of a Cask for Bore Tools 4
3. Branch Pipe Welding/cutting Tool 6
3-1. Constitution of Welding/cutting Tool 6
3-2. Performance Tests of Welding/cutting Tool 8
3-3. Welding/cutting Tests with Bore Tool 10
3-4. Conclusion 27
4. Manifold Welding/cutting Tool 28
4-1. Constitution of Welding/cutting Tool 28
4-2. Performance Test of Welding/cutting Tool 30
4-3. Alignment Characteristic Test 30
4-4. Welding/cutting Tests 31
4-5. Conclusion 33
5. Non-destructive Inspection Tool for the Branch Pipe 35
5-1. Sensor Arrangement 35
5-2. Constitution of Non-destructive Inspection Tool 37
5-3. Performance Test of the Non-destructive Inspection Tool 38
5-4. Inspection Characteristic Test 38
5-5. Conclusion 39
6. Branch Pipe Leak Detection Tool 41
6-1. General 41
6-2. Constitution of Leak Detection Equipment 42
6-3. Performance Test of Leak Detection Head 43
6-4. Leak Detection Performance Test 43
6-5. Leak Detection Performance Test Results 44
7. Composite Fiber for YAG Laser Welding/cutting Tool 45
7-1. Constitution of the Composite Fiber 45
7-2. Observation Test 46
7-3. Conclusion 46
8. Conclusions 48
Acknowledgments 50
References 50
JAERI-Tech 99-048
Appendix 163
A. YAG Laser Welding/cutting Characteristics 163
A-l. Welding/cutting Tests with Dual YAG Laser 163
A-2. Welding/cutting Tests with High Power YAG Laser 168
B. Leak Detection Methods and Tests 209
B-l. Experimental Data on Leak Detection and Localization 209
IV
JAERI-Tech 99-048
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JAERI-Tech 99-048
1. Introduction
1-1. Task objective
The objective of this task is to develop the remote bore tools for welding, cutting and inspection
of the blanket cooling pipe from the inside. The bore tools are inevitably required for the blanket
cooling pipe maintenance since an external space around the pipe to be welded, cut and inspected is
too narrow to access. According to the current machine layout, the bore tools should be designed to
move at least 15 m along the cooling pipe so as to reach the position where the pipe is welded, cut and
inspected. In addition, the operation of welding, cutting and inspection has to be performed under
high gamma radiation dose rate of 3xlO6 R/h.
1-2. Scope of the report
The development of the remote maintenance technology is essential to realize ITER , because
the reactor components are activated by 14-MeV neutrons. Particularly, the in-vessel components,
such as divertor cassettes and blanket modules, are the most critical ones in terms of maintenance of
the reactor. The blanket module is categorized into the scheduled maintenance which includes
complete change out from shielding to breeding. Therefore, reliable and quick maintenance
operations are highly required for the blanket module. Figure 1.1 shows a schematic view of the
blanket module maintenance proposed for ITER. After the cooling pipes of the blanket module are
cut, blanket modules are removed through the horizontal port using an in-vessel manipulator and
transporter. A number of cooling pipes are connected to the modules through a relatively narrow
space located behind the modules, so that the external space around the pipes is not sufficient to allow
an access of an ordinary TIG welder or mechanical cutter.[2,3,4] [5]
A new maintenance technology based on a CCh laser beam and a YAG laser beam has
been developed for welding and cutting of cooling pipes by the internal access. The YAG laser
system based on laser beam transmission using a flexible optical fiber inside the pipe has been
selected since the pipe welding/cutting by the internal access can be available even for the pipes with
bend and branch.
The remote bore tools based on YAG laser for welding/cutting are essential technology with
regard to the realization of the current modular type blanket concept. The main issues relating to this
technology are mobility of the tool to move inside the pipe through several bend sections for
accessing to the branch pipe, controllability for positioning, welding and cutting, and qualification of
welding and cutting including edge preparation and misalignment.
A prototypical processing head was fabricated and tested to demonstrate the fundamental
mobility for traveling inside a 100 mm pipe with a bend radius of 400 mm and for accessing from
the 100 mm pipe to a branch pipe with a diameter of 50 mm . In addition, welding and cutting
experiments using the ordinary YAG laser system was conducted in order to specify the welding and
cutting conditionsI61.
As next development, this head has been improved to be compacted and to add the traveling
mechanism. The welding and cutting experiments using the optical parts of this head has been also
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JAERI-Tech 99-048
conducted in order to specify the welding and cutting conditions including effects such as gaps,
filler and so on. In parallel, the welding/cutting tool for the manifold, the non-destructive inspection
head and the leak detection head for the branch pipe have been designed and fabricated.
This report covers the following results obtained from the prototypical processing head
fabrication and welding, cutting and inspection experiments.
(1) Second step branch pipe tool for welding/cutting using YAG laser with the traveling
mechanism
Design, fabrication and functioning tests of a prototypical processing head and traveling
mechanism developed for welding/cutting of branch pipe from cooling manifold
(2) Manifold tool for welding/cutting using YAG laser with the alignment mechanism for the
manifold pipe
Design, fabrication and functioning tests of a prototypical processing head and alignment
mechanism developed for welding/cutting of manifold
(3) YAG laser welding and cutting for pipe and thick plate
1) Welding experiments including effects of gaps, laser power and process speed on
weldability
2) Cutting experiments as a function of process speed, laser power and assist gas
3) Rewelding experiments using samples cut by YAG laser
4) Mechanical tests of welded samples with different conditions
5) Filler welding and inter layer metal welding experiments with gaps
(4) Non-destructive inspection tool for branch pipe with the traveling mechanism
Design, fabrication and functioning tests of a prototypical non-destructive inspection head
and traveling mechanism developed for the welded region inspection of branch pipe from
cooling manifold
(5) Leak detection tool for branch pipe
Design, fabrication and functioning tests of a prototypical leak detection head developed
for the welded region inspection of branch pipe from cooling manifold
(6) Complex fiber for the YAG laser welding/cutting
Design, fabrication and basic test of a prototypical complex fiber developed for the
welding, cutting and observing at the processing point
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JAERI-Tech 99-048
2. Design Concept for The Blanket Maintenance
2-1. Design conditions
According to the ITER EDA design, the blanket is composed of blanket modules poloidally
segmented, strong back plates and cooling manifolds located between the modules and the back
plates. The cooling manifolds are attached to the back plate and each module is connected to the
back plate individually. In this configuration, a branch pipe has to be connected between the
manifold and the module for cooling. The proposed bore tool systems are based on the internal
access type equipment. The welding/cutting tools for branch pipe and manifold can be available
even for the pipes with bend section and branch because the laser beam transmission using a flexible
optical fiber installed inside the pipe. The non-destructive inspection tool and leak detection tool can
be also available inside the pipe because the compact and easy handling type sensor is installed on
each tool.
Figure 2.1 shows a schematic view of the procedure of branch pipe maintenance from the
inside of the cooling manifold: these heads can be moved through the cooling manifold with a
minimum bending radius of 400 mm. They have the following features;
(1) Traveling mechanism through the cooling manifold with curved sections
(2) Telescopic mechanism to approach from the manifold to branch pipe for
welding/cutting/inspecting
(3) Position adjustment and fixing mechanism for welding/cutting/inspecting
In this study, specifications of the blanket cooling pipe are considered as listed in Table 2.1
and the environmental conditions are listed in Table 2.2, which are prepared by JCT as the design
guideline. Figure 2.2 shows the basic pipe layout proposed in the upper area of the blanket for
allowing the access of the bore tools from outside.
Table 2.1 Specifications of the blanket cooling pipe
Main pipe (manifold)
Branch pipe
Minimum radius of curvature
SS316L, 100A, thickness of 6 mm
SS316L, 50A, thickness of 3 mm
400 mm
Table 2.2 Environmental conditions
Item
Atmosphere
Pressure
Temperature
Radiation
Contamination
Magnetic field
Condition
dry nitrogen or ambient air
1 bar
<50°C
< 3 x 106 R/hr
tritium, activated dust, beryllium
zero
o
JAERI-Tech 99-048
Figure 2.3 shows a schematic view of the procedure of manifold maintenance from the inside
of the cooling manifold: these heads can be moved through the cooling manifold with a minimum
bending radius of 400 mm. They have the following features;
(1) Traveling mechanism through the cooling manifold with curved sections
(2) Alignment mechanism for fixing the manifold in order to weld/cut/inspect
(3) Position adjustment and fixing mechanism for welding/cutting/inspecting head
2-2. Design concept of a cask for bore tools
A cask of the bore tools is located outside of the bio-shield and the tools for
welding/cutting/inspecting are inserted from the end of the pipe vertically extended. Figure 2.4
shows a schematic view of the cask desired for this purpose. In the cask, a tool changer system is
installed for inserting/extracting the welding/cutting/inspecting equipment. The details are described
as follows;
(1) Cask conditions for the bore tools
To design the bore tool cask, the following conditions are assumed;
- Vertical access to approach the blanket cooling manifolds
- Several casks located around the reactor
- Movable range of 90 degrees per one cask
- Four types cask
1) Double seal door cask
The handling tool of double seal door and plug handling tool are installed in a cask.
2) Bore tool cask for branch pipe
The welding/cutting tool and weld inspection tool for branch pipe are installed in a cask.
3) Bore tool cask for main pipe
The welding/cutting tool and weld inspection tool for main pipe are installed in a cask.
4) Leak detection cask
The leak detection tool for main pipe and branch pipe are installed in a cask.
(2) Specifications of the bore tool cask
- Toloidal movement around the reactor
- Four cable winding tools are installed in the cask
- Two welding/cutting tools and two weld inspection tools are installed in the cask.
(3) Specifications of cable handling unit
a) Winding drum
- Method : spring back style, simple line, multiple layered drum
- Cable winding length : about 25 m
- Cable winding layer : 7 layers
- Cable tension : 2 ~ 7.2 kgf
- Winding torque : 1400 ~ 4900 kgf-mm
b) Supply drum
- Method : rubber disk with pinching drum
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JAERI-Tech 99-048
- Cable feeding speed : max. 3 m/min
- Drum rotation torque : ~ 16000 kgf-mm
- Cable sending force : 34.1 kgf
- Cable pinch force : 22.7 kgf
(4) Specifications of tool changer unit
- Positioning method : offset guide pipe
- Pushing system : gas cylinder
- Rotation system : warm gear
- Adjustment speed and method
• X axis : 10 mm/sec - screw drive
• Z axis : 94.2 mm/sec - gas cylinder, lac&pinion
• 9 axis : 5 rpm - turn gear
Figures 2.5 and 2.6 show schematic views of the cask layout for the bore tools and power
source. They are installed in the crane hall and the distance should be minimized in terms of data
acquisition. In order to operate the 4 sets of systems at the same time, each cask is installed at 90
degree intervals. After the blanket branch pipes are cut, the blanket modules are removed through
the horizontal ports using in-vessel manipulators and transporters.
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JAERI-Tech 99-048
3. Branch Pipe Welding/Cutting Tool
In the previous study, the processing head of welding/cutting tool has been designed161. It is
consisted of four vehicles in order to realize the functions of welding, cutting and positioning. Each
head is connected by universal joints and driving power is transmitted by flexible tubes. Though
some issues were remained, the first trial of the development of welding/cutting tool was successful.
To resolve the remaining issues, a new welding/cutting tool has been designed and its key features are
described in the following sections.
3-1. Constitution of welding/cutting tool
The proposed YAG laser welder/cutter is based on laser beam transmission using a flexible
optical fiber installed inside the pipe. Therefore, welding/cutting by means of internal access can be
performed even for the pipes with bends and branches. The YAG laser welder/cutter and weld
inspection tools (see chapter 5) for the branch pipes have been designed to satisfy the following
requirements.
1) Axial traveling mechanism through the cooling manifold with an inner diameter of 102.3 mm
and the curved sections with a bend radius of 400 mm (minimum).
2) Telescopic mechanism to access from the cooling manifold to the branch pipe with an inner
diameter of 54.5 mm for welding and cutting.
3) Position detection, adjustment and fixing mechanism for welding and cutting.
Figure 3.1 shows the fabricated YAG laser processing head and Fig. 3.2 shows structural
design of the welding/cutting processing head. This system is composed of four vehicles which are
processing heads and traveling heads. Their external diameters are below 97 mm. The main
components of this system are optical fiber, lens and mirrors for the laser transmission, motors for
drives, and sensors for positioning.
(1) Optical transmission mechanism
This is to transmit the YAG laser beam from the external source. The optical fiber is
made of synthetic quartz to tolerable for radiation hardness and covered by the flexible tube
which is also used to supply assist and shield gases for the welding/cutting processes.
Figure 3.3 shows a schematic view of the transmission tube. Total length of the optical
fiber is 20 m and the core diameter is 0.6 mm. In order to reflect and focus the laser, lens
and mirror are installed in front of the fiber. Lenses are made of synthetic quartz and
mirrors are made of Oxygen Free Hard Copper (OFHC), which are also chosen in terms of
radiation hardness.
(2) Positioning mechanism
Since accurate positioning of the processing head within the range of 0.1 mm is required
for welding by YAG laser, this system is designed to have 4-axes freedom, which are Z, 9,
R and p axes as shown in Fig. 3.4. Due to the space constraint and minimum curvature
requirement, the system is divided into 2 vehicles. For final adjustment, a sleeve of R axis
and a disk type positioning pin which are driven by air cylinders on the second head are also
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JAERI-Tech 99-048
installed on the first head. These vehicles are connected by a flexible tube made of stainless
steel. The major specifications of the positioning mechanism of each axis are described
below.
1) Zaxis
Movement direction : movement for fine adjustment of the processing head
along the axis of the manifold
Allowable stroke : 20 mm
Movement speed : 30 mm/sec
The driving air is transmitted using a tube from the outside to the Z axis movement
mechanism composed of a pneumatic cylinder.
2) 0 axis
Movement direction : rotation of the processing head around the axis of the
manifold
Rotation angle : < 360 degree
Rotation speed : 16 sec/rev
3) R axis
Movement direction : telescopic movement of the welding/cutting nozzle into a
branch pipe axis
Allowable stroke : 37 mm
Movement speed : 0.3 mm/sec
Operational range of the nozzle is between 14.4 mm and 22.4 mm from the surface of
manifold outside diameter.
4) p axis
Movement direction : rotation of the welding/cutting nozzle around the axis of
the branch pipe
Rotation angle : < 360 degree
Rotation speed : 15 sec/rev
5) sleeve of R axis
Function : final adjustment of the welding/cutting nozzle into a
branch pipe axis
The driving air is transmitted using a tube from the outside to the sleeve movement
mechanism composed of a pneumatic cylinder.
6) disk type positioning pin
Function : final adjustment to the direction of the manifold axis
The driving air is transmitted using a tube from the outside to the disk type positioning
pin movement mechanism composed of a pneumatic cylinder.
(3) Sensors for detecting the position of a branch pipe
A sensor for detecting the position of a branch pipe are installed at the top of the
processing head. Eddy current type sensor is chosen due to its compactness and precision.
n
JAERI-Tech 99-048
By traveling the processing head in the manifold, the edge of a branch pipe can be detected
while the head moves along the manifold. In addition, two rollers are installed on the
second head in order to measure the traveling distance. These are pushed against internal
surface of the manifold and are rolled along the one. In this way, the position of the
processing head can be measured to the branch pipe to be welded/cut.
(4) Centering mechanism
Centering mechanisms based on motor and air cylinder are installed in the welding/cutting
processing head. Four pins, which are driven by DC-servo motor, are arranged in front of
the welding/cutting processing head and can be contacted to the internal surface of the
manifold so as to adjust the center of the head to the manifold axis. In addition, back
supports, which are driven by air cylinder, are also arranged on backside of the processing
head.
(5) Traveling mechanism
Figure 3.5 shows details of the traveling trucks. Each truck is composed of two pads
connected to pushing and sliding mechanisms for axial movement like an inchworm as
shown in Fig. 3.6. The pads surface is grooved to increase friction between pads and pipe
wall. The flexible stainless tube containing the utility cables, gas tube and fiber is deployed
from a storage drum follow the axial movement of the trucks. The desired specifications of
the trucks are described below.
- Tractive force : 30 Kg
- Traveling distance : 30 m with 4 bending parts
- Moving posture : all direction
- Function
• To pass through the cable into the body
• To increase the traveling head
3-2. Performance tests of welding/cutting tool
In order to verify the basic functions and characteristics of the fabricated YAG laser system, the
processing head for welding/cutting has been tested and the results are as follows:
(1) Driving mechanisms of the processing head
All driving mechanisms were tested to verify the allowable movement stroke, rotation
angle and operation speed. The results are summarized in Table 3.1 and it is concluded
that the driving mechanisms can be operated satisfactorily and their operation ranges meet the
design values.
JAERI-Tech 99-048
TableAxis name
RF(front support)
RS(back support)
Z
P
R
e
Disk pin
Sleeve stopper
3.1 Test resultsRange of
movement
9 mm
10 mm
20 mm
360°
37 mm
0 ~ 360 °
6 mm
5 mm
of each mechanism movementMovement speed
0.20 mm/s
(20 mm/s)*
(20 mm/s)*
12.9s/rev
1.27 mm/s
14.8 sec/rev
(30 mm/s)*
(30 mm/s)*
Actuator
DC motor x 4
Air cylinder x 2
Travelingmechanism
DC motor x 1
DC motor x 1
DC motor x 1
Air cylinder x 1
Air cylinder x 1
* design value
(2) Traveling mechanism
All driving mechanisms were tested to verify the allowable movement stroke and operation
speed. The results are summarized in Table 3.2 and it is concluded that the traveling
mechanisms can be operated satisfactorily and their operation ranges meet the design values.
It is found that the real traveling speed of the bore tool is 0.5 m/min. The storage drum has
the sensor which can detect the cable looseness for the cable sending/rewinding. The
rotation of the storage drum is synchronized with the traveling of the tool movement using
the sensor.
TableAxis name
Truck Apushing padTruck Asliding screwTruck Bpushing padTruck Bsliding screw
Cable winding
3.2 Test resultsRange of
movement
8 mm
60 mm
8 mm
60 mm
4 rotation
of traveling mechanismMovement speed
3 mm/s
20 mm/s
3 mm/s
20 mm/s
0.5 m/min
Actuator
DC motor x 2
DC motor x 4
DC motor x 2
DC motor x 4
DC motor x 1
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JAERI-Tech 99-048
3-3. Welding/cutting tests with bore tool
As mentioned above, the welding/cutting processing head by YAG laser for the blanket
maintenance has been fabricated for branch pipe welding/cutting. In parallel with this development,
welding, cutting and rewelding tests and more advanced tests have been conducted using the
fabricated welding/cutting tool and the industrial 2 kW YAG laser source system in order to qualify
the welding, cutting and rewelding conditions, including the effect of gaps and processing position.
Figure 3.7 shows the mock-up tests system which is composed of two bent pipes, one
straight pipe and one straight pipe with a branch part. Inner diameter of all pipes is about 100 mm.
The detailed specifications of the pipes are listed below. This system can provide the various
posture of welding/cutting tool in order to adapt each blanket position as shown in F ig .3.8 . The
laser source has an optical fiber with a core diameter of 0.6 mm and a length of 20 m. The fiber is
connected to the welding/cutting tool. When welding/cutting tests are conducted, a test pipe is
attached to the branch part.
(Fe=bal., Cr=16.3%, Ni=12.7%, Mo=2.1%, C=0.02%,
Test pipeMaterial
Manifold
Inner diameter
Thickness
Maximum curvature
Branch pipe
Inner diameter
Thickness
:SS316L
(Fe=bal.,
P=0.023<
: 102.3 mm
: 6 mm
:400 mm
: 54.5 mm
: 3 mm
3-3-1. Basic welding test
In this test, the welding conditions were surveyed using SS316L pipes with a thickness of 3
mm as functions of laser power, welding speed, defocus distance and gaps, as listed below. The
edge preparation of the test pipes was machined and the groove was inclined with the angle of 20
degrees.
Laser power : 900, 1000, 1100 W
Frequency : 40 Hz
Duty : 50 %
Welding speed : 0.4, 0.5, 0.6 m/min
Shield gas : Nitrogen
Gap quantity : 0,0.5, 1.0, 1.5 mm
Work distance : 2 mm
Defocus distance : -1.0, 0, +1.0, +1.5 mm
Tool posture : level (similar to No.7 blanket)
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JAERI-Tech 99-048
3-3-1-1. Dependency of defocus, laser power and welding speed
The dependency of defocus, laser power and welding speed on the welding quality has been
investigated. In this test, the butt weld without gaps was adopted. The following tests were
performed for the qualification; (1) appearance and macroscopic test, (2) radiographic testing (RT)
and (3) tensile test.
(1) Appearance and macroscopic test
Figure 3.9 shows the results of bead appearance and macroscopic test as a parameter
of defocus. In all cases of defocus, the bead penetration to the back surface was observed
at the laser power of 1100 W and the welding speed of 0.5 m/min. This result shows that
the misalignment of the nozzle positioning between -1.0 and +1.5 mm is allowed.
Figure 3.10 shows the results of bead appearance and macroscopic test as a parameter
of laser power. In the case of 900 W, partial penetration was observed at the defocus of +1
mm and the welding speed of 0.5 m/min. Other cases have shown full penetration
welding.
Figure 3.11 shows the results of bead appearance and macroscopic test as a parameter
of welding speed. In the case of 0.6 m/min, the bead penetration to the back surface was
barely observed. Other cases have shown full penetration welding.
(2) Radiographic testing (RT)
All test pipes welded satisfied the RT regulation(lst grade) and there was no blowhole.
(3) Tensile test
Tensile tests were carried out for all test pipes welded. Table 3 .3 , 3.4 and 3.5
show the tensile test results of various cases. The characteristics of the base metal is shown
as follows: 1) tensile strength is 529 MPa, 2) proof stress is 249 MPa, 3) elongation is 65
%, here, each value is average of three test pieces.
Tensile strength and elongation were remarkably decreased in case of laser power of 900
W due to less welding penetration. It seems that the values of the others did not change
very much.
- 1 1 -
JAERI-Tech 99-048
Defocus
(mm)
-1.0
0
+1.0
+1.5
Table 3
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
.3 Results of tensile tests in the
Proof stress
(MPa)
273
270
282
275
244
256
274
258
281
255
264
267
289
282
285
285
Tensile
strength (MPa)
522
524
540
529
516
514
524
518
528
495
530
518
559
534
553
549
parameter of defocus
Elongation (%)
57
48
54
53
56
46
56
53
54
55
46
52
59
52
44
52
Break part
welded part
base metal
base metal-
welded part
welded part
base metal-
base metal
base metal
base metal-
base metal
base metal
base metal
-
[Welding conditions] Laser power : 1100 W, Welding speed : 0.5 m/min
Table 3.4
Laser
power (W)
900
1000
1100
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Results of tensile tests in the parameter of laser
Proof stress
(MPa)
231
257
252
247
231
264
271
255
281
255
-264
267
Tensile
strength (MPa)
466
532
503
500
532
521
533
529
528
495
530
518
Elongation (%)
36
50
39
42
57
54
59
57
54
55
46
52
power
Break part
welded part
base metal
welded part
-
welded part
base metal
base metal
-
base metal
base metal
base metal
-
[Welding conditions] Welding speed : 0.5 m/min, Defocus : 0 mm
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JAERI-Tech 99-048
Table 3.5
Speed
(m/min)
0.4
0.5
0.6
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Results of tensile tests in the parameter of welding speed
Proof stress
(MPa)
258
277
259
265
231
264
271
255
285
272
262
273
Tensile
strength (MPa)
532
518
509
520
532
521
533
529
521
532
510
521
Elongation (%)
55
51
52
53
57
54
59
57
32
51
42
42
Break part
base metal
base metal
base metal
-
welded part
base metal
base metal-
welded part
base metal
base metal
-
[Welding conditions] Laser power : 1000 W, Defocus : 0 mm
3-3-1-2. Effect of gaps
The dependency of gaps(sliding gap) at the edge preparation on the welding quality has been
investigated. In this test, the gaps ranging from 0 to 1.5 mm were examined under the conditions
of 1100 W laser power and 0.5 m/min welding speed. The following tests of all samples were
performed for the qualification; (1) appearance test, (2) radiographic testing (RT), (3) macroscopic
test, (4) tensile test.
(1) Appearance test
Figure 3.12 shows the appearance test results. In the case of the 1.0 and 1.5 mm
gaps, partial penetration was observed in sliding part. Other cases have shown full
penetration welding.
(2) Radiographic testing (RT)
All samples satisfied the 1st grade in the RT regulation and there was no blowhole
although the penetration was lacked in the cases of both 1.0 and 1.5 mm gap.
(3) Macroscopic test
Figure 3.13 shows the cross section of welding penetration and a wine cup type
penetration was observed. In the case of 0.5 mm gap, however, the bead on the backside
is not appeared and the cases of 1.0 and 1.5 mm gap have clearly shown the under cut
penetration.
(4) Tensile test
The tensile test results are shown in Table 3.6. The tensile strength and elongation are
decreased with increasing of gap. As a whole, the maximum allowable gap for YAG laser
- 1 3 -
JAERI-Tech 99-048
welding without filler material is considered to be around 0.5 mm from the tensile test results
and the macroscopic tests.
3-3-1-3. Summary of basic welding tests
1) Optimum conditions of welding
From the test results, the optimum conditions as the parameters of defocus, laser power
and welding speed are shown as follows.
Defocus
Laser power
Welding speed
: 1100 W
: 0.5 m/min
2) Allowable gap
A maximum allowable gap is estimated to be around 0.5 mm.
Table 3.6 Results of tensile tests in the parameter of gaps
Gap
(mm)
0
0.5
1.0
1.5
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Proof stress
(MPa)
244
256
274
258
275
290
276
280
224
264
222
237
-
276
205
241
Tensile
strength (MPa)
516
514
524
518
520
547
559
542
332
510
533
458-
544
489
517
Elongation (%)
56
46
56
53
33
47
40
40
15
45
43
34-
48
37
43
Break part
welded part
welded part
base metal-
welded part
base metal
base metal-
welded part
base metal
welded part-
-
base metal
welded part
-
[Welding conditions] Laser power: 1100 W, Welding speed : 0.5 m/min, Defocus : 0 mm
3-3-2. Basic cutting test
In this test, various of cutting conditions have been surveyed using SS316L pipe with a
thickness of 3 mm. Cutting conditions of examined are as follows:
- 1 4 -
JAERI-Tech 99-048
Laser power : 900, 1000, 1100 W
Frequency : 40 Hz
Duty : 50 %
Cutting speed : 0.7, 0.8, 0.9 m/min
Assist gas : Nitrogen, 100 1/min
Work distance : 2 mm
Defocus distance : -1.0, 0, +1.0 mm
Tool posture : level (similar to No.7 blanket)
3-3-2-1. Cutting test
The dependency of laser power, cutting speed and defocus on the cutting characteristics has
been investigated using assist gas of nitrogen. The following items were performed for the
qualification; (1) appearance test and macroscopic test, (2) measurement of cutting surface
roughness.
(1) Appearance and macroscopic test
Cutting tests were carried out under various conditions of laser power, cutting speed and
defocus. In all conditions, it is not found the striking change on the appearance and
macroscopic. Figure 3.14, 3.15 and 3.16 show the appearance and macroscopic test
results. In addition, the dross height was measured under various conditions. The dross
height was between 1.1 and 1.6 mm. It is not found the striking change.
(2) Roughness of cutting surface
Table 3.7 shows the results of roughness measurement of cutting surface as a parameter
of defocus. In the case of -1.0 mm, Ra and Rmax are the largest value compared with
other cases.
Table 3.8 shows the results of roughness of cutting surface as a parameter of laser
power. In the case of 900 W, Ra and Rmax are the largest value compared with other
cases.
Table 3.9 shows the results of roughness of cutting surface as a parameter of cutting
speed. In the case of 0.9 m/min, Ra and Rmax are the largest value compared with other
cases.
- 1 5 -
JAERI-Tech 99-048
Table 3.7 Results of the roughness of cutting surface in the parameter of defocus
Defocus (mm)
-1.0
0.0
+1.0
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Ra (jim)
10.2
9.4
11.0
10.2
7.0
12.2
7.6
8.9
10.4
6.6
8.0
8.3
Rmax (p,m)
72.2
79.4
76.0
75.9
46.0
82.6
64.6
64.4
62.6
45.0
68.4
58.7
[Cutting conditions] Laser power : 1000 W, Cutting speed : 0.8 m/min
Table 3.
Power (W)
900
1000
1100
8 Results of the roughness of cutting surface
in the parameter of laser power
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Ra (|im)
10.4
12.6
8.4
10.5
10.4
6.6
8.0
8.3
9.6
8.0
9.4
9.0
Rmax (|im)
78.0
85.2
80.6
81.3
62.6
45.0
68.4
58.6
60.6
56.4
59.2
58.7
[Cutting conditions] Defocus : +1.0 mm, Cutting speed : 0.8 m/min
- 1 6 -
JAERI-Tech 99-048
Table 3.9 Results of the roughness of cutting surface
in the parameter of cutting speed
Speed (mm)
0.7
0.8
0.9
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Ra (u.m)
6.8
9.4
8.6
8.3
10.4
6.6
8.0
8.3
10.4
9.6
9.8
9.9
Rmax (p.m)
53.2
54.4
66.6
58.1
62.6
45.0
68.4
58.6
68.6
71.4
88.0
76.0
[Cutting conditions] Defocus : +1.0 mm, Laser power : 1000 W
3-3-2-2. Summary of cutting tests
From these test results mentioned above, the following cutting conditions should be adopted:
Defocus : 0 mm
Laser power : 1000 W
Cutting speed : 0.8 m/min
Following rewelding tests mentioned below were carried out using these samples.
3-3-3. Rewelding test
To verify the reweldability of the laser cutting surface, rewelding tests were performed under
the following conditions. In this test, the laser cutting samples with assist gas of nitrogen was
welded to new SS316L pipe with machining surface. After the rewelding tests, (1) bead appearance
tests, (2) radiographic testing (RT), (3) macroscopic observation and (4) tensile tests were performed
for the welding qualification:
: 1100 W
:40Hz
: 5 0 %
: 0.5 m/min
: Nitrogen
: 2mm
: 0 mm
: level (similar to No.7 blanket)
Laser power
Frequency
Duty
Rewelding speed
Shield gas
Work distance
Defocus distance
Tool posture
- 1 7 -
JAERI-Tech 99-048
(1) Appearance and macroscopic tests
Figure 3.17 shows the bead appearance and the cross-section of welding penetration
after the rewelding. Full penetration was observed on welded part although the dross was
attached around the pipe.
(2) Radiographic testing (RT)
This sample has shown the 1st grade in the RT regulation.
(3) Tensile test
Tensile tests were carried out after rewelding. Table 3.10 shows the tensile test
results. From this result, the mechanical properties of laser cutting sample is very similar to
the normal welding sample which is described in the section of the basic welding. As a
result, rewelding of the laser cutting samples can be possible.
Table 3.10 Results of tensile tests in the rewelding
Combination
Machining
+
Laser cutting
No.
1
2
3
Ave.
Proof stress
(MPa)
264
267
266
266
Tensile
strength (MPa)
533
514
526
524
Elongation
(%)
62
54
60
59
Break part
base metal
base metal
base metal
-
[Rewelding conditions]
Defocus : 0 mm, Laser power : 1100 W, Welding speed : 0.5 m/min
3-3-4. Welding/cutting test on different posture
To verify the welding/cutting qualification on the different posture of the bore tool, the
welding/cutting quality tests were performed on No. 1, 7 and 13 blanket positions. In this test, the
location of No. 1 blanket was assumed to the manifold angle of 28 degree against the ground. In the
same way, No.7 was 83 degree and No. 13 was 8 degree.
[Welding conditions]
: 150 W (positioning test), 1100 W (qualification test)
:40Hz
: 5 0 %
: 0.5 m/min
: Nitrogen
: 2 mm
: 0 mm
: No.l (= 28°), No.7 (= 83°) and No. 13 (= 8°)
Laser power
Frequency
Duty
Welding speed
Shield gas
Work distance
Defocus distance
Tool posture
[Cutting conditions]
Laser power
Frequency
:1000 W
:40Hz
- 1 8 -
JAERI-Tech 99-048
Duty
Welding speed
Assist gas
Work distance
Defocus distance
Tool posture
:50%
: 0.8 m/min
: Nitrogen, 100 1/min
: 2 mm
: 0 mm
:No.l (=28°), No.7 (= 83°) and No. 13 (= °)
3-3-4-1. Positioning accuracy test in the welding
The dependency of the blanket location on the welding characteristics has been investigated
using the mock-up tests system. The gap between a half of the weld zone width and the groove
was measured after the welding. The measurement positions were 0, 90, 180 and 270 degree of
the branch pipe, respectively. The welding conditions are listed below:
Table 3.11 shows the test result of the positioning accuracy in the welding. In the case of
No. 1 blanket, the positioning gap per one loop of the branch pipe was ±0.12 mm. In the same
way, No.7 was ±0.19 mm and No. 13 was ±0.11 mm. The maximum error range between
greatest and smallest value per a measurement position was 0.34 mm in the case of the blanket
position changed.
Table 3.11 Results of the positioning accuracy tests in the welding
Measurement
Position
1
2
3
4
Error
Blanket No.
No.1
(angle = 28°)*
-0.12
-0.35
-0.31
-0.18
±0.12
No.7
(angle = 83°)
-0.05
-0.25
-0.04
0.13
±0.19
No.13
(angle =8°)
-0.29
-0.43
-0.27
-0.21
±0.11
Error
0.24
0.18
0.27
0.34
-
* angle means the tool position against the ground unit: [mm]
3-3-4-2. Positioning accuracy test in the cutting
The dependency of the blanket location on the cutting characteristics has been investigated using
the mock-up tests system. The length of the cut branch pipe was measured after the cutting.
The measurement positions were 0, 90, 180 and 270 degree of the branch pipe.
Table 3.12 shows the test result of the positioning accuracy in the cutting. Each value
means the branch pipe length from the edge. In the case of No. 13 blanket, the positioning error
per one loop of the branch pipe was ±0.27 mm, which was maximum value in this test. The
maximum error in all test results on repeatability was ±0.30 mm on the No.3 position.
- 1 9 -
JAERI-Tech 99-048
Table 3.12 Results of the
Blanket No.
No.1
(angle =28°)
No.7
(angle =83°)
No.13
(angle =8°)
Test No.
1
2
3
1
2
3
1
2
3
Repeatability
positioning accuracy tests in the cutting
Measurement position
1
50.80
50.79
50.74
50.50
50.40
50.49
50.57
50.41
50.45
±0.20
2
50.97
50.95
50.94
50.62
50.65
50.67
50.92
50.93
50.97
±0.18
3
50.93
50.90
50.90
50.38
50.34
50.45
50.79
50.78
50.74
±0.30
4
50.77
50.75
50.76
50.29
50.26
50.40
50.40
50.47
50.51
±0.26
Error
±0.10
±0.10
±0.10
±0.17
±0.20
±0.14
±0.27
±0.27
±0.27
-
* angle means the tool position against the ground unit: [mm]
3-3-4-3. Qualification test of the welding
To verify the effect of the blanket location, qualification tests were performed in various
postures of the bore tool.
After the welding test on different posture, (1) bead appearance tests, (2) radiographic testing
(RT), (3) liquid penetrate testing (PT), (4) tensile tests (No. 13 blanket), (5) macroscopic
observation tests and (6) measurement of shrinkage quantity were performed for the welding
qualification.
(1) Appearance tests
Figure 3.18 shows the bead appearance of welding penetration after the welding. Full
penetration was observed on welded part in all cases.
(2) Radiographic testing (RT)
All test samples show the 1st grade in the RT regulation.
(3) Liquid penetrant testing (PT)
Figure 3.19 shows the results of the liquid penetrant testing. No crack is shown on
all test samples.
(4) Tensile test
Tensile tests were carried out after welding. Table 3.13 shows the tensile test results.
From this result, although the mechanical properties of laser welding sample in nitrogen is
reduced to about 30 MPa compared with the base metal, the break part was on the base
metal. In the other hand, the mechanical properties of laser welding sample in the air was
very similar to the base metal's one.
- 2 0 -
JAERI-Tech 99-048
Table 3.13 Results of tensile tests in the various posture
Item
Base metal
No.13 blanket
(angle = 8°)
in nitrogen
No.13 blanket
(angle =8°)
in air
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Proof stress
(MPa)
277
279
281
279
230
244
243
239
256
246
250
251
Tensile strength
(MPa)
506
493
511
503
452
484
474
470
499
470
482
484
Break part
base metal
base metal
base metal
-
base metal
base metal
base metal
-
welded metal
base metal
base metal
-
(5) Macroscopic observation tests
Figure 3.20, 3.21 and 3.22 show the cross section of the weld region in the various
posture welding. The full penetration is observed in all cases.
(6) Measurement of shrinkage quantity
Table 3.14 shows the shrinkage quantity of the test samples which are not used for
tensile tests. As the test results, the length of test samples was shrunken to 0.42 mm in
average.
Table 3.14 Shrinkage quantity in the various posture welding
Blanket
No.
No.1
(= 28°)
No.7
(= 83°)
Ave.
Test
No.
1
2
3
1
2
3
-
Measurement position
1
65.65
65.68
65.57
65.70
65.71
65.52
-
2
65.65
65.56
65.77
65.58
65.51
65.60
-
3
65.61
65.47
65.68
65.39
65.41
65.50
-
4
65.51
65.46
65.68
65.56
65.64
65.49
-
Ave.
65.61
65.54
65.70
65.56
65.57
65.53
-
Shrinkage
quantity
0.39
0.46
0.30
0.44
0.43
0.47
0.42
unit: [mm]
- 2 1 -
JAERI-Tech 99-048
3-3-4-4. Qualification test of the cutting
To verify the effect of the blanket location, qualification tests were performed in various
postures of the bore tool.
After the cutting test on different posture, (1) appearance tests and (2) macroscopic tests were
performed for the cutting qualification.
(1) Appearance tests
Figure 3.23 shows the appearance test results after the cutting. Although the dross
with dispersion was attached around the cutting surface, the similar appearance was
observed in all cases.
(2) Macroscopic tests
Figure 3.24 shows the cross section of the cutting samples. Although the dross was
attached outside of pipes, the cutting surface was smooth.
3-3-4-5. Summary of welding/'cutting test on different posture
From these tests, the following results are obtained in all cases;
(1) From welding test results, all test samples were obtained the 1st grade in the RT
regulation..
(2) From PT results, the crack is not appeared on the welding region.
(3) From tensile test results, welded parts have the tensile strength as same as base metal.
(4) From cutting test results, it is found that rewelding is available because the cutting surface
is smooth.
3-3-5. Repeat welding/cutting test
To verify the repeatability of the laser cutting and rewelding, repeat welding/cutting tests were
performed on a NC table with high positioning accuracy. In this test, the laser cutting samples were
welded to new SS316L pipe with machining surface. The patterns of repeat tests are listed as Table
3.15. The maximum frequency of repeat welding is assumed 5 times. To verify the
welding/cutting qualification on the different posture of the bore tool, the welding/cutting quality tests
were performed on No.7 and 13 blanket positions. The location of No.7 blanket was assumed to
the manifold angle of 83 degree against the ground. In the same way, No. 13 blanket was 8 degree.
After the repeat welding tests, (1) 3-dimensional measurement of the pipe shape, (2) bead appearance
tests and macroscopic observation, (3) radiographic testing (RT), (4) liquid penetrant testing (PT) and
(5) tensile tests were performed for the welding qualification:
[Welding conditions]
Laser power : 1100 W
Frequency : 40 Hz
Duty : 50 %
Welding speed : 0.5 m/min
Shield gas : Nitrogen
Work distance : 2 mm
- 2 2 -
JAERI-Tech 99-048
Defocus distance
Tool posture assumed
Pattern) a,b,c,d,e
Pattern) e
[Cutting conditions]
Laser power
Frequency
Duty
Welding speed
Assist gas
Work distance
Defocus distance
Tool posture assumed
Pattern) a,b,c,d,e
Pattern) e
: 0 mm
: No. 13 blanket (angle = 8 degree)
: No.7 blanket (angle = 83 degree)
:1000 W
:40Hz
:50%
: 0.8 m/min
: Nitrogen, 100 1/min
: 2 mm
: 0 mm
: No. 13 blanket (angle = 8 degree)
: No.7 blanket (angle = 83 degree)
Table 3.15 Repeat test patterns
Pattern
a
b
c
d
e
Procedure of test
3D measurement -> Welding -> 3D measurement -> RT -> PT ->
Appearance test -> Macroscopic test
3D measurement -> Welding -> Cutting -> Welding -> 3D measurement
-> RT -> PT -> Appearance test -> Macroscopic test
3D measurement -> Welding -> Cutting -> Welding -> Cutting -> Welding
-> 3D measurement -> RT -> PT -> Appearance test -> Macroscopic test
3D measurement -> Welding -> Cutting -> Welding -> Cutting -> Welding
-> Cutting -> Welding -> 3D measurement -> RT -> PT -> Appearance
test -> Macroscopic test
3D measurement -> Welding -> Cutting -> Welding -> Cutting -> Welding
-> Cutting -> Welding -> Cutting -> Welding -> 3D measurement -> RT ->
PT -> Appearance test -> Macroscopic test
3-3-5-1. Qualification tests of repeat weldingl cutting
(1) 3-dimensional measurement of the pipe shape
Figure 3.25 shows the 3-D measurement position of the welded branch pipe. After
every welding, the shrinkage quantity of the samples was measured. From Tables 3.16
to 3.21 show the change of the branch pipe diameter every welding. The maximum
deviation between "before welding" and "after welding" was 0.88 mm at 5 times welding as
shown in Table 3 . 1 9 .
- 2 3 -
JAERI-Tech 99-048
From Figures 3.26 to 3.30 show the relation between measurement position and
shrinkage quantity. The maximum shrinkage was -0.5 mm to the direction of the radius as
shown in Fig .3.30.
Table 3.16 Results of shrinkage quantity at position of blanket side : a2
Cycle
1
2
3
4
5
Inner diameter
Before welding^
54.50
54.49
54.50
54.48
54.49
After welding
54.33
54.32
54.36
54.35
54.34
Deviation
0.17
0.17
0.14
0.13
0.15
unit: [mm]
Table 3.17 Results of shrinkage quantity at position of blanket side : b2
Cycle
1
2
3
4
5
Inner diameter
Before welding
54.50
54.49
54.49
54.48
54.50
After welding
54.42
54.41
54.39
54.41
54.42
Deviation
0.08
0.08
0.10
0.07
0.08
unit: [mm]
Table 3.18 Results of shrinkage quantity at position of blanket side : c2
Cycle
1
2
3
4
5
Inner diameter
Before welding
54.50
54.49
54.50
54.48
54.50
After welding
54.48
54.48
54.46
54.46
54.48
Deviation
0.02
0.01
0.04
0.02
0.02
unit: [mm]
- 2 4 -
JAERI-Tech 99-048
Table 3.19 Results of shrinkage quantity at position of manifold side : a1
Cycle
1
2
3
4
5
Inner diameter
Before welding
54.47
54.47
54.47
54.48
54.48
After welding
54.24
54.09
54.02
53.92
53.60
Deviation
0.23
0.38
0.45
0.56
0.88
unit : [mm]
Table 3.20 Results of shrinkage quantity at position of manifold side : b1
Cycle
1
2
3
4
5
Inner diameter
Before welding
54.48
54.48
54.47
54.48
54.48
After welding
54.34
54.28
54.23
54.20
54.05
Deviation
0.14
0.20
0.24
0.28
0.43
unit: [mm]
Table 3.21 Results of shrinkage quantity at position of manifold side : d
Cycle
1
2
3
4
5
Inner diameter
Before welding
54.47
54.47
54.48
54.48
54.47
After welding
54.43
54.41
54.39
54.40
54.36
Deviation
0.04
0.06
0.09
0.08
0.11
unit: [mm]
(2) Appearance and macroscopic tests
Figure 3.31 shows the results of repeat cutting from 2 to 5 times. The asperity on the
weld bead was increasing as the welding times were increasing. However, there was no
porosity in the welding region even 5 times welding as shown in Fig. 3 .32. In the case of
No.7 blanket (83°), there was no change as compared with another cases. It is shown in
Fig.3.33.
(3) Radiographic testing (RT)
- 2 5 -
JAERI-Tech 99-048
All test samples show the 1st grade in the RT regulation. From this result, it is found
there are no defect and no bad fusion in the weld region.
(4) Liquid penetrant testing (PT)
Figure 3.34 shows the results of the liquid penetrant testing. In the case of No.7
blanket (83°), Fig .3.35 shows the results of the liquid penetrant testing. No crack is
shown on all test samples.
(5) Tensile tests
Tensile tests were carried out in the cases of 3 and 5 times welding. Table 3.22
shows the tensile test results. From this result, the mechanical properties of repeat laser
welding is very similar to the base metalFls one. As a result, 5 times repeat welding of the
laser cutting samples can be possible.
Table
Item
Base metal
3 cycle
5 cycle
3.22 Results of tensile
No.
1
2
3
Ave.
1
2
3
Ave.
1
2
3
Ave.
Proof stress
(MPa)
277
279
281
279
293
279
229
267
275
270
263
269
tests in the repeat welding
Tensile strength
(MPa)
506
493
511
503
501
498
466
488
519
509
520
516
Break part
base metal
base metal
base metal-
base metal
base metal
base metal
-
base metal
base metal
base metal
-
3-3-5-1. Summary of repeat weldinglcutting
From these tests, the following results are obtained;
(1) All test samples welded from 1 to 5 times satisfied the 1st grade in the RT regulation.
(2) From PT results, the crack is not appeared on the welding region in all cases.
(3) From tensile test results, welded parts show the same tensile strength as that of the base
metal.
(4) From 3-D measurement test results of the pipes, it is found that welding shrinkage is
increased in proportion to the number of welding. As results, it is confirmed that the
repeat welding is possible at least by 5 times.
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JAERI-Tech 99-048
3-4. Conclusion
The YAG laser type welding/cutting tool for branch pipes of module type blankets has been
developed and tested under the various conditions, and the realization of the branch pipe maintenance
was confirmed. In particular, this system can be moved inside a 100-A pipe with a minimum
curvature of 400 mm and the welding/cutting nozzle with telescopic mechanism can be extended into a
branch pipe with a diameter of 50 mm for welding/cutting. In addition, this system is designed to
have 5 axes freedom so as to position the welding/cutting nozzle within the required accuracy for
welding/cutting. The centering mechanisms and position sensors are also facilitated for positioning
and fixation of the processing head. In parallel with this tool development, welding, cutting,
rewelding and repeat welding experiments using YAG laser have been performed to clarify the
optimum welding and cutting conditions including the effects of gaps and assist gas on the weldability
and reweldability. From these tests, the following conclusions are obtained:
1) The optimum conditions of welding are listed below.
Laser power :1100W
Frequency :40 Hz
Duty : 50 %
Welding speed : 0.5 m/min
Shield gas : Nitrogen
Work distance : 2 mm
Defocus distance : 0 mm
2) A maximum allowable gap for welding is to be around 0.5 mm without filler materials.
3) The optimum conditions of cutting are listed below.
Laser power : 1000 W
Frequency : 40 Hz
Duty : 50 %
Welding speed : 0.8 m/min
Assist gas : Nitrogen, 100 1/min
Work distance : 2 mm
Defocus distance : 0 mm
4) Rewelding of the laser cutting surface can be performed with keeping similar mechanical
properties to those of machining surface.
5) Welding/cutting in the various posture is available.
6) Repeat welding/cutting on the same part is available by 5 times.
7) The traveling method is stepping type such as an inchworm and the traveling speed of the
tool is 0.5 m/min in the manifold with bent and curved sections.
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JAERI-Tech 99-048
4. Manifold Welding/Cutting Tool
4-1. Constitution of welding/cutting tool
(1) Manifold conditions
The manifolds are cut, welded and inspected so as to replace the Class-3 components classified
unscheduled maintenance during the machine life, such as Vacuum Vessel and super conducting
magnets. The manifolds are routed from upper port to cryostat and bio-shield through the guard
pipe which provides the secondary boundary of cooling water, as shown in Fig. 4 . 1 .
The blanket manifold conditions are summarized below.
a) Outer diameter
b) Thickness
c) Minimum curvature
d) Material
e) Assumption of maximum gaps before welding
114.3 mm
6.0 mm
R400mm
SS316L
50 mm (axial direction)
10 mm (lateral direction)
(2) Constitution of the tool
Figure 4.2 shows the structural design of the manifold welding/cutting tool and Figure 4.3
shows the fabricated processing head. A 4 kW YAG laser transmitted through the flexible optical
fiber is adopted for this tool. The processing head is composed of two trucks fitted with a clamping
mechanism to align and fix prior to welding and a processing mechanism for welding/cutting. The
clamping mechanism consists of two hooks fitted to the front and rear of the trucks with air actuators.
The processing head can be moved inside the cooling manifold by connecting it to the traveling trucks
similar to branch pipe welding/cutting tool.
The welding/cutting mechanism has three axes, head rotation (6 axis), nozzle lateral movement
(R axis) and nozzle axial movement (Z axis). The manifold pulling mechanism has two axes,
alignment hooks clamping (C axis) and three front alignment hooks axial movement (Zl axis). The
specifications of these axes are summarized below,
a) 0 axis
Movement direction : rotation of the head around the axis of manifold
Movement mechanism : motor and gear
Stroke : ±225 degree
Movement velocity : 4.75 rpm
b) R axis
Movement direction : lateral movement for nozzle adjustment
Movement mechanism : motor and rack & pinion
Stroke : 5 mm
Movement velocity : 64.3 mm/sec
c) Z axis
Movement direction : axial movement for nozzle adjustment
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JAERI-Tech 99-048
Movement mechanism : motor and ball screw
Stroke : 10 mm
Movement velocity : 2.71 mm/sec
d)C axis
Movement direction : clamping of alignment hooks
Movement mechanism : air cylinder
Stroke : 15 degree
e)Zl axis
Movement direction : axial movement of front alignment hooks
Movement mechanism : motor and ball screw
Stroke : 60 mm
Movement velocity : 0.3 mm/sec
(3) Optical system
A 4 kW YAG laser transmission is composed of an optical fiber with a core diameter of 1.0
mm, four lenses with synthetic quartz and a reflection mirror with Cu. The specifications of laser
transmission are summarized below,
a) Optical fiber
Type : step index
Core diameter : 1.0 mm
Length : 10 m
b) Lens
Material : synthetic quartz
c) Reflection mirror
Material : Cu
(4) Operation procedure
Figures 4.4 and 4.5 show the cutting operation procedure. The tool is positioned roughly
by the optical image fiber on processing mechanism and the encoder on traveling truck. After the
rough positioning, the tool is fixed by clamping hooks and the 3 mm height pre-installed projection
on the inner surface of cooling manifolds. The nozzle position is decided by the monitoring of He-
Ne laser transmitted through the optical image fiber. The nozzle is extended close to the inner
surface of cooling manifold by R axis motor and the plunger pre-installed on nozzle keeps the
constant distance between nozzle and manifold.
Figures 4.4 and 4.6 show the welding operation procedure. After the rough positioning of
tool, the tool pulls the cooling manifold using clamping hooks for final alignment and fixation before
welding. The clamping mechanism is designed to produce clamping forces of about 500 kgf and to
close the axial gaps of 50 mm and the lateral gaps of 10 mm to the final alignment required for
welding with alignment cone on the outer surface of cooling manifolds.
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JAERI-Tech 99-048
4-2. Performance test of welding/cutting tool
The performance tests were performed in order to verify the basic functions and characteristics
of the fabricated tool. Test results are summarized below.
(1) Welding/cutting mechanism
Three axes were tested to verify the allowable movement stroke. The results are shown in
Table 4 . 1 .
Table 4.1 Test results of welding/cutting mechanism
Test item
Range of movement
Axis name
eR
Z
Design value
±225 deg.
5 mm
10 mm
Measurement result
±225deg.
5.1 mm
10.2 mm
(2) Clamping mechanism
Two axes were tested to verify the allowable movement stroke, and Zl axis was also tested to
verify the clamping force. The results are shown in Table 4 .2.
Table 4.2 Test results of clamping mechanism
Test item
Range of movement
Force
Axis name
C
Z1
Z1
Design value
15 deg.
60 mm
467 kgf
Measurement result
15 deg.
60.4 mm
467 kgf
4-3. Alignment characteristic test
The alignment test was performed to verify the alignment characteristics of fabricated tool.
Figure 4.7 shows the test stand pre-installed springs for simulation of flexibility similar to bellows
and Table 4.3 shows the test results. In this test, the spring constants in axial direction and lateral
direction were 4.76 kgf/mm and 3.68 kgf/mm, respectively. The allowable gaps for pipe welding
are 0.8 mm in axial direction and 2.0 mm in lateral direction, as mentioned in Appendix A-3.
Table 4.3 Results of alignment test (Pipe clamping force : 467 kgf)
Pipe gaps before alignment
Axial direction
25 mm
50 mm
Lateral direction
10 mm
10 mm
Pipe gaps after alignment
Axial direction
0 mm
0 mm
Lateral direction
1.0 mm
0.8 mm
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JAERI-Tech 99-048
4-4. Welding/cutting tests
The pipe welding/cutting tests using fabricated bore tool and test stand were performed in order
to clarify the welding/cutting abilities of tool. In these tests, the tool and nozzle positions inside pipe
were adjusted by an operator prior to welding/cutting.
(1) Cutting test
This test was conducted using SS316L pipes with a thickness of 6.0 mm and an inner diameter
of 102.3 mm under the optimum conditions, which had been obtained in the last basic cutting tests
(Ref. Appendix A-3), as follows;
Laser power : 3.0 kW (PW), Peak power of 6.0 kW
Duty : 50 %
Defocus : 0 mm
Stand off : 1 mm
Cutting speed : 0.3 m/min
Shield gas : Nitrogen, 120 1/min
In this test, however, the cutting speed was changed from 0.6 m/min to 0.3 m/min in order to
increase the heat input into a pipe. The increase of heat input was considered to be able to obtain the
good result in all cutting positions and to prevent the miss-cutting due to the change of stand off
during cutting operation.
The cutting time and the temperature of mirror were 64 second and maximum 140 degree,
respectively. The following tests were performed for the cutting quality; a)cutting appearance and
b)surface roughness.
a) Cutting appearance
Figure 4.8 shows the result of cutting appearance. The dross attached to a pipe is not almost
observed.
b) Surface roughness
The result of surface roughness is max. 131 micro meters. This is twice as a value of basic
cutting test result. It is why that the weld metal increases due to the increase of heat input into a
pipe.
(2) Welding test
This test was conducted using SS316L pipes with a thickness of 6.0 mm and an inner diameter
of 102.3 mm under the optimum conditions, which had been obtained in the last basic welding tests
(Ref. A-3), as follows;
Laser power : 3.6 kW (CW)
Defocus : -1 mm
Stand off : 3 mm
Welding speed : 0.3 m/min
Gap quantity : 50 mm (axial direction)
: 10 mm (lateral direction)
Shield gas : Nitrogen, 501/min
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JAERI-Tech 99-048
Butt type : I butt
The pipe was aligned before welding by the tool. An image fiber on nozzle could monitor the
inner surface of pipe during the alignment operation. Figure 4.9 shows the image of inner surface
of pipe obtained by the image fiber.
The welding time and the temperature of mirror were 64 second and 209 degree, respectively.
The temperature of mirror exceeded the allowable temperature of 200 degree. In addition, the top of
nozzle was melted. It was found that these troubles were caused by the decline of nozzle due to a
reaction force of flexible optical fiber. The YAG laser transmitted through the declined nozzle was
reflected at the inner surface of pipe and was exposed to the top of nozzle. Finally, the heat input
into a nozzle melted the top of nozzle and increased the temperature of mirror by thermal conduction.
The following tests were performed for the welding qualification; a) bead appearance and
macroscopic test, b) radiographic test (RT) and c) tensile strength and elongation tests.
a) Bead appearance and macroscopic test
Figure 4.10 shows the results of bead appearance and macroscopic test. The lack of penetration
bead is observed. In addition, the bead appearance by flat position welding differs from overhead
position.
b) Radiographic test (RT)
The porosity was not observed.
c) Tensile strength and elongation tests
The results of tensile strength and elongation tests are 485.70 MPa (83.31 % relative strength) and
24.41 % (49.82 % relative elongation), respectively. The lack of penetration bead causes the low
tensile strength and elongation. In particular, the tensile strength is not satisfied with the allowable
value of 490MPa.
(3) Re-welding test
The little modification of tool was performed prior to the re-welding test. In the welding tests,
it was found that the nozzle declined and swayed due to a reaction force by a flexible optical fiber.
For this, the optical fiber was fixed by a fiber support inside tool for the prevention of nozzle decline.
In this test, the SS316L pipes which were used for the previous cutting test were welded to a
new SS316L pipe, under the same conditions as welding test. In this test, as cut welding was
adopted.
Laser power
Defocus
Stand off
Welding speed
Gap quantity
Shield gas
3.6 kW (CW)
-1 mm
3 mm
0.3 m/min
50 mm (axial direction)
10 mm (lateral direction)
Nitrogen, 501/min
The welding time and the temperature of mirror were 64 second and 178 degree, respectively.
The temperature of mirror was below the allowable temperature of 200 degree. The following tests
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JAERI-Tech 99-048
were performed for the re-welding qualification; a)bead appearance and macroscopic test, b)
radiographic test (RT) and c) tensile strength and elongation tests.
a) Bead appearance and macroscopic test
Figure 4.11 shows the results of bead appearance and macroscopic test. The good penetration
bead is obtained.
b) Radiographic test
The porosity was not observed.
c) Tensile strength and elongation tests
The results of tensile strength and elongation tests are 527.37 MPa (90.46 % relative strength) and
30.00 % (61.22 % relative elongation), respectively. These are higher than the welding test
results because of the good penetration bead.
(4) Summary
The pipe cutting/welding/re-welding tests using the fabricated tool were performed. In these
tests, the characteristics and welding/cutting ability of tool were clarified. The good cutting/re-
welding test results were obtained.
It was found that the stand off could not be kept in a certain value during welding/cutting due to
the reaction force by a flexible optical fiber. The modification of R axis which drives nozzle in
lateral direction will be needed.
4-5. Conclusion
The bore tool for blanket manifold welding/cutting was fabricated and verified the
characteristics through the performance test, the pipe alignment test and the pipe welding/cutting tests.
In addition, this system is designed to have 5 axes freedom so as to position the welding/cutting
nozzle within the required accuracy for welding/cutting. The clamping mechanism is also developed
and tested about the alignment between the pipes. In parallel with this tool development,
welding/cutting/rewelding experiments using YAG laser have been performed to clarify the optimum
welding and cutting conditions. From these tests, the following conclusions are obtained:
(1) The good result of pipe alignment by fabricated tool was obtained. The tool is able to
accommodate 10 mm axial gap and 50 mm lateral gap to allowable gaps for welding, respectively.
(2) The optical image fiber on nozzle is able to observe inner surface of pipe. For this, the
alignment procedure can be monitored by tool. In the future, the monitoring tests of
welding/cutting will be performed by means of the in-process monitoring (Ref. Appendix A-2)
or the direct monitoring of inner surface.
(3) The welding/cutting conditions are summarized below,
a) Cutting
Laser power : 3.0 kW (PW), Peak power of 6.0 kW
Duty : 50 %
Defocus : 0 mm
Stand off : 1 mm
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JAERI-Tech 99-048
Cutting speed : 0.3 m/min
Shield gas : Nitrogen, 1201/min
b) Welding/re-welding
Laser power : 3.6 kW (CW)
Defocus : -1 mm
Stand off : 3 mm
Welding speed : 0.3 m/min
Gap quantity : 50 mm (axial direction), 10 mm (lateral direction)
Shield gas : Nitrogen, 50 1/min
It was found that the nozzle could not be kept in a certain position during welding/cutting due to the
reaction force by a flexible optical fiber. The modification of R axis will be needed in order to avoid
the nozzle sway in the future.
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JAERI-Tech 99-048
5. Non-Destructive Inspection Tool for The Branch Pipe
For surface crack detection of pipe welds, Electro-Magnetic Acoustic Transducer (EMAT) was
selected in terms of radiation hardness, high temperature application and no couplant requirement.
The EMAT, which is basically composed of a magnet and a coil to generate ultra-sonic waves, is
conventionally used for the non-destructive inspection of nuclear power plants welds. The main
technical issue for ITER apphcations is to increase the radiation hardness and the detectabihty of
defects for pipe welds within a constrained space. The irradiation tests of EMAT units were
conducted at a dose rate of about 10 kGy/hr with no significant degradation observed up to 10 MGy.
To increase the detectability, a new sensor configuration, in which wave transmitter and receiver is
arranged in various position, was adopted and a share horizontal (SH) wave was applied.
5-1. Sensor arrangement
5-1-1. Position of the transmitter and receiver
An EMAT sensor is constructed by two elements, whose functions are to transmit and to
receive the ultra-sonic waves respectively. They are usually arranged around the cracks and detect
the signal to/from the cracks. To optimize the arrangement of each element, three arrangement
methods of the sensor, which were transmission, tandem and reflection technique as shown in
Fig. 5 . 1 , were examined. Table 5.1 shows the EMAT's specifications for the arrangement test in
the branch pipe.
Table 5.1 EMAT's specifications for arrangement tests
Frequency
Wave mode
Magnet
- Material
-Height
-width
700 kHz
SH ultrasonic wave
SmCo, 8 elements
7.5 mm
5.0 mm
Beam angle
Heat proof temp.
Coil
- Material
- Length
- Width
about 64.4 °
150 °C
polyamide based
30 mm
12 mm
(1) Transmission technique
Figure 5.2 shows the result of the transmission technique. The transmitter and receiver
of EMAT are arranged at both sides of weld point. An ultrasonic wave runs along the pipe.
In the case of this technique, the reflected echo level becomes small because the ultra-sonic
wave is passed through the weld region. In addition, the shape is to be long in the pipe.
(2) Tandem technique
Figure 5.3 shows the result of the tandem technique. The transmitter and receiver of
EMAT are arranged on the same straight line. The receiver which is located behind the
transmitter catches an ultrasonic wave from the defect. The distance from the transmitter to the
JAERI-Tech 99-048
receiver through the defect is so long that the high signal level is expected. However, the
shape is to be long in the pipe as same as transmission technique.
(3) Reflection technique
Figure 5.4 shows the result of the reflection technique. The transmitter and receiver of
EMAT are arranged such as a letter of ' V . The receiver catches the echo from the defect.
The reflected signal level is low compared with other methods because the surface of magnets is
flat and can not touch the surface of the pipe. The shape is compact more than other methods
because of 'V shape.
Table 5.2 shows the results of the sensor arrangement. The tandem and reflection
techniques were better than the transmission. Though the tandem technique is required more large
size to improve the sensitivity, the reflection technique has the possibility of improvement in
detectability. From the test results and the space constraint in the branch pipe, the reflection
technique is adapted to the non-destructive inspection method and the improvement of the sensor is
expected by refabrication.
Technique
Transmission
Tandem
Reflection
Table 5Path
length
X
short
•Aa littlelong
long
.2 The resultsUltrasonic
noise
X
exist anotherpath signal
X
exist anotherpath signal
exist echofrom weld
shape
of the arrangement testShape
Along
length
Along
length
largewidth
Sensitivity
X
little change
Alow flaw echo
level
Alow flaw echo
level
Total estimate
X
difficult todiscriminate
without noiseA
low sensitivity
Alow sensitivity
Figure 5.5 shows the test result of the refabricated EMAT for 50A pipe. The EMAT's
surface is shaped to inner curvature of 50A pipe.
5-1-2. Angle of the transmitter and receiver
To improve the detectability of EMAT, the optimum angle between a transmitter and a receiver
was examined. In this test, the angle was changed from 80 to 120 degree per 10 degree and a test
piece of flat plate was adapted as shown in Fig. 5.6. The specifications of EMAT is same as the
arrangement test as shown in Table 5 .1.
Figures 5.7 and 5.8 show the wave form of the angle test results. Figure 5.9 shows the
comparison result of S/N level on sensor angle. In the case of the angle of 100 degree, S/N level
shows the best sensitivity on both inside and outside defect. The angle of 26 degree had been tested
in the arrangement test as mentioned above. According to the comparison of 26 and 100 degree, it is
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JAERI-Tech 99-048
found that the sensitivity of them is obviously deferent. From these results, it is chosen that the
angle of EMAT is 100 degree.
5-1-3. Lift-off of sensor
An EMAT does not need a couplet for contacting an object. However, the surface of EMAT
must be attached to the object in order to detect a defect. From a viewpoint of the contact between an
EMAT and an object, a lift-off test was carried out. Figure 5.10 shows the result of the lift-off
test. It is found that the sensitivity of sensor is increasing as the quantity of lift-off is decreasing.
From this result, the EMAT must be attached to an object surface with a small compression force.
5-2. Constitution of non-destructive inspection tool
To detect defects of weld region of a branch pipe, an internal pipe inspection tool has been
studied and designed. The design conditions are same as the welding/cutting tool which is
mentioned in the chapter 3. In the case of the welding/cutting tool, however, it is required that the
optical fiber, which transmits the laser power, is positioned in the center of the tool in order to keep
the precise laser processing. Thus, the welding/cutting tool was selected to the inchworm type
traveling trucks. The non-destructive inspection tool has no constraint conditions to keep the
enough space in the tool center. As a result, a wheel type traveling truck is adopted to move in
cooling manifolds.
Figure 5.11 shows the fabricated non-destructive inspection tool. The system is composed
of six vehicles which are two traveling trucks, an inspection unit, a rotation unit, a distance sensor
unit and a connection unit. The external diameters are below 94 mm which is considered about
oblateness of the bent pipe.
(1) Specification of the weld inspection sensor
Figure 5.12 shows the appearance of fabricated EMAT. The specifications of EMAT are
listed below;
- Inspection method : EMAT
(Electro-Magnetic Acoustic Transducer)
- Frequency : 700 kHz
- Wave mode : SH ultrasonic wave
- Beam angle : about 64.4 °
- Magnet : SmCo, 7 elements
- Coil : polyamide based
- Arrangement : V position (reflection technique), angle of 100 °
- Dimension (EMAT is shaped inner surface of 50A pipe)
• Length : 26 mm (including case)
• Width : 16 mm
• Height : 14 mm
(2) Specification of each unit
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JAERI-Tech 99-048
Figures 5.13 ~ 5.18 show the tool appearance of each unit. Table 5.3 shows the
specifications of each axis movement and the centering performance is listed below.
a) Inspection head and rotation unit
- Centering dia. range : 86 ~ 108 mm
b) Distance detection unit
- Centering dia. range : 90 ~ 159 mm
- Detection distance : non restriction
Table 5.3 Specifications of the tool movement
Axis name
EMATup &down
EMATrotation
Toolrotation
Symbol
R
P
e
Scanning range
27 mm
±185 deg.
±185deg.
Scanning speed
20mm/sec
90deg./sec
75.9deg./sec
Insertionstroke
28 mm
-
-
5-3. Performance test of the non-destructive inspection tool
In order to verify the basic functions and characteristics of the fabricated non-destructive
inspection tool, the traveling trucks has been tested and the results are as follows:
(1) Design conditions of traveling head
: > 1.0 m/min
: movable force between the cask and the farthest branch
- Traveling speed
- Tractive force
- Positioning accuracy
- Connection method
- Rescue method
(2) Specification of the traveling head
The following results are obtained;
- Centering dia. range
- Movement distance range
- Movement speed
- Tractive force
- Positioning accuracy (error)
pipe
:± 10 mm
: universal link connection, possible to increase other
truck
: possible to release the pipe pushing force
: 86 ~ 108 mm
; non restriction
: max. 1.5 m/min with cable handling
: average 40 kgf with two traveling trucks
: within 3 ~ 4 % under all cases
5-4. Inspection characteristic test
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JAERI-Tech 99-048
In order to verify the basic functions and characteristics of the fabricated EMAT for branch
pipes, the sensor has been tested and the results are as follows:
Figure 5.19 shows the appearance of EMAT for setting inspection tests and schematic view
of the artificial defects.
(1) Conditions of the basic performance test
The prototype EMAT for pipes was arranged and tested in reference technique (V arrangement).
Test conditions are listed below;
Objective : SS316L pipe with thickness of 3 mm
inner diameter of 54.5 mm
: YAG laserWelding condition
Defect shape
-Depth
- Inside defect size
- Outside defect size
Location of defect
(2) Test results
Table 5.4 show the test results of the non-destructive inspection with EMAT and Fig .5 .20
shows the example of test results.
Table 5.4 Results of the non-destructive inspection with EMAT
: 0, 20, 30 % depth of pipe thickness
: 15 mm long (34.4°), 0.3 mm width
15 mm long (30.7°), 0.3 mm width
surface and back near weld point with 1 mm
Depthof slit
30 %*
20 %t
10 %t
A: Base metal(inside)
ft
ft
A
B : Base metal(outside)
ft
ft
A
C :Across weld(inside)
ft
ft
X
D : Across weld(outside)
ft
X
X
5-5. Conclusion
The non-destructive inspection tool for the welding pipe has been successfully fabricated and
the applicability to the blanket branch pipe inspection has been demonstrated. The system can be
also moved inside a 100-A pipe with a minimum curvature of 400 mm and the inspection nozzle with
telescopic mechanism can be extended into a branch pipe with a diameter of 50 mm for the non-
destructive inspection. In this tool, the EMAT which is one of the non-destructive inspection
methods was adopted and tested. The crawler type traveling trucks are adopted to this system
because of no space constraint for installation of optical fiber such as the branch and manifold
welding/cutting tool. In parallel with this tool development, non-destructive inspection tests using
EMAT have been performed to clarify the sensitivity of the inspection ability. From these tests, the
following conclusions are obtained:
1) Specifications of the weld inspection sensor are listed below;
- Inspection method : EMAT
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(Electro-Magnetic Acoustic Transducer)
- Frequency : 700 kHz
- Wave mode : SH ultrasonic wave
- Beam angle : about 64.4 °
- Magnet : SmCo, 7 elements
- Coil : polyamide based
- Arrangement : V position (reflection technique), angle of 100 °
- Dimension (EMAT is shaped inner surface of 50A pipe)
• Length : 26 mm (including case)
•Width :16 mm
• Height : 14 mm
2) The EMAT can detect 10 % defect on a base metal and 20 % defect across a weld region.
3) The traveling speed of the tool is faster than l.Om/min in the manifold with bent and
curved sections.
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6. Branch Pipe Leak Detection Tool
6-1. General
Leak detection is essential to confirm reliability and quality of cooling pipe welding. This
chapter describes leak detection methods and test results of leak detection head designed and
developed. Table. 6.1 show the design conditions of leak detection tool. Table.6.2 and
Fig. 6.1 summarize the leak detection sensitivity of various detection methods and typical leak
detection method.
(1) Design conditions
Table 6.1 Design conditions of leak detectionAtmosphere
PressureTemperature
RadiationContaminationMagnetic field
Target detectable sensitivity
Dry N2 or inert gas1 bar
<50°C3 x 106 Rad/hr
Tritium, activated dust, berylliumZero
< 1 x 10"7 Pa • m3/sec
(2) Sensitivity of various detection methods
Table 6.2 Sensitivity of detection methodsMethod
Vacuum
Compression
Detectiontype
lonizationgauge
Helium leakdetector
MassanalyzerBabble
Ammoniatest
Halogentest
Sniffer
Measurement style
Detector
Detector
Detector
VisualVisual
Detector
Detector
Tracer gas orliquid
C4Hio,H,CO2He
He, H, Ar
H2O,N2NH3,Air
Halogen
He
Pressure(Pa)
0.13 to 1.3x10-6
< 1.3 x 10-2
1.3x10-2to 1.3x10-10
3x106< 2 x 106
< 1.5 x 106
< 1 x 105
Min. detectableleak
(Pa*m3/s)10-8
10-11
10-11
4x10-710-8
10-7
10-8
(3) Leak detection process for the ITERFigure 6 .2 shows a general leak detection process for the blanket cooling pipe.
(4) Selection of leak detection method for the ITERA leak detection method for the blanket cooling pipe should be selected on the basis of the
conditions mentioned above and experimental data obtained in large size tokamaks as well as
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JAERI-Tech 99-048
compatibility with remote handling under severe gamma radiation. The data obtained in tokamak
experience and the 1st stage tool experiment is attached to Appendix B.
As a conclusion, a probe method using a nude type ionization vacuum gauge and a sniffer
method using a helium leak detector were selected as the candidates of leak detection method.
6-2. Constitution of leak detection equipment
In order to verify the leak detection performance, partial models of detection heads were
fabricated, together with mockup of blanket cooling pipe, in accordance with the Japanese industrial
Standards (JIS). The main features of the detection heads and pipe mockup are described below.
(1) Mockup of blanket cooling pipe
Figure 6.3 and 6.4 show an overall structure of the fabricated mockup which is composed oftwo blanket manifolds, two branch pipes, vacuum pump and a movement mechanism to move aleak detection head in the axial direction. The arrangement of the cooling pipes simulates theblanket cooling pipes, including orifice to reproduce a conductance of blanket module andcooling pipes.
The orifice is designed taking into account the real pipe arrangement shown in F ig .6 .5 .Figure 6.6 represents the analysis model to calculate the conductance. In order to simulate aleak, several variable standard leaks are installed at the positions of branch pipe welding joints.
1) Mockup of blanket cooling pipeManifold pipe : JIS 100A sch 40Branch pipe : JIS 50A sch 40Orifice conductance :7.1 x 10-4m3/secDummy leak position : 80mm of branch pipe from manifold centerHelium leak rate : Less than 1.2 x 10-9 pa*m3/sUltimate pressure : 2.2 x 10-5 p a
(2) Partial model of detection headFigure 6.7 shows the fabricated detection head using probe method. This head is composed
of a commercial base nude gauge and mechanical jacks to insert the head into the branch pipe.This tool can be moved along the pipe axial direction using the movement mechanism.
A directional nozzle was attached to the detection head so as to increase detectability. The sizeof directional nozzle was specified in accordance with the tokamak experience as shown inFig.6.8.
Figure 6.9 shows the fabricated detection head using sniffer method. A sniffer tube isattached to the same head structure as the probe method, so that the sniffer tube can access to thebranch pipe welding joints.
The main parameters of the fabricated detection heads are listed below.
1) Ionization probe head (Probe method)Gauge size : OD26 mm, L39 mm (commercial product)Detectable pressure : to 10-6 p a
Directional nozzle size : ED9 mm, L22 mm2) Sniffer tube head (Sniffer method)
Tube size : OD0.9 mm, L25 m
- 4 2 -
JAERI-Tech 99-048
6-3. Performance test of leak detection head
Before the leak detection test, function of axial and radial movement mechanism has been tested
and confirmed.
The results are summarized below and it has been found that all mechanism are functioned,
i) Axial direction
Movement Range : Max. 680 mm
Movement speed : Variably (to Max. 2000 mm/min)
ii) Radial direction
Movement Range : Max. 50 mm
Movement speed : Variably (to Max. 200 mm/min)
6-4. Leak detection performance test
In case of the probe method, the detection head was moved inside the pipe after evacuation ofpipe so as to detect standard leak located at the branch pipe welding joints. Table. 6.3 summarizesthe testing conditions of the probe method.
Table 6.3 Test conditions of Probe method
Pipe outer atmosphere
TemperaturePipe inner pressure (Pa)
Leak rate (Pa*m3/sec He)
Scanning directionScanning speed
Leak position
Air/1 bar.
RTorder 10-41.8 x 10-7
Radial direction
25 mm/min uniformity1A
On the other hand, in case of sniffer method, the inside of pipe was filled with nitrogen, whichis used as a carrier gas (viscous flow), for detection of the standard leak, as schematically shown inFig .6 .10. In this case, the sniffer tube is not inserted into the branch pipe. Table 6.4summarizes the testing conditions of the sniffer method.
Table 6.4 Test conditions of Sniffer method
Pipe outer atmosphere
TemperatureScanning direction
Axial direction scanning speedRadial direction scanning speed
Leak rate (Pa*m3/sec He)Leak position
Carrier gas
Carrier gas flow rate
Pipe inner pressure
Air/1 bar.
RT
Axial and Radial direction200 mm/min
25 mm/min2.0x10-4,8.0x10-7
Branch pipe 1A, 1A+2A
Dry Nitrogen
11 l/min
9.3 KPa
Notes : Refer to Figs. 6.11 and 6.12 which show the schematic diagram of detectionmethods.
- 4 3 -
JAERI-Tech 99-048
6-5. Leak detection performance test results
The results of both methods are listed in Table 6.5 and the details of the data obtained are
shown in Fig. 6.13 to F ig .6.15 . From this result, the probe method can detect 1.8x10-7
Pa*m3/sec He at a vacuum pressure of 10-4 p a inside the pipe. On the other hand, snifer method
detects 2x10-4 ~ 8x10-4 Pa*m3/sec He depending on the number of leak location.
Table 6.5 Performance test parameter and resultsDetection method
Branch pipe leak positionLeak rate (Pa*m3/sec He)
Pipe inner pressureCarrier gas flow rateScanning directionScanning speed
Probe
1A1.8x10-710-4 Pa
-
Radial25 mm/min
Sniffer
1A2.0x10-49.3 kPa11 l/minAxial
200 mm/min
1A+2A8.0x10-4
9.3 kPa11 l/min
Axial200 mm/min
- 4 4 -
JAERI-Tech 99-048
7. Composite Fiber for YAG Laser Welding/Cutting Tool
The pipe welding/cutting has to be carried out under the severe gamma-ray conditions in a
limited space inside the pipe. Therefore, no extra space is available to install monitoring equipment
for welding/cutting operation. A solution of this problem is to prepare a composite fiber for laser
energy and images transmission. A composite fiber whose functions are YAG laser transmission
for welding/cutting and images transmission for monitoring has been developed with radiation
hardness type fiber scope and optical parts. It consists of one fiber for laser transmission and a
number of small fibers located around the fiber for images transmission. This section describes the
construction of the composite fiber and the result of basic performance tests.
7-1. Constitution of the composite fiber
The proposed composite fiber has two functions which are laser transmission and images
transmission. YAG laser is transmitted through a fiber whose diameter is 0.6 or 0.7 mm. It
depends on the laser power to weld or cut. For image transmission approximately 3,000 ~ 20,000
fibers with a diameter of 9 or 10 |J.m are arranged around the fiber for laser transmission. The
purpose of this study is to combine two types of fibers which have a different diameter and to develop
the optical parts in order to share the high power laser and the image data. Figure 7.1 shows the
conceptual design of the composite fiber. The futures of this fiber are listed below;
1) One fiber for laser transmission is positioned in the center of the composite fiber to perform
the precise laser focusing for welding/cutting.
2) The image fibers are installed around the laser transmission fiber for monitoring, and to
collect and analyze the scattered laser light during welding/cutting in order to assure the
quality.
3) Replacement from a normal laser transmission fiber to the composite fiber is easy because
the total diameter of the fiber is only about 2 mm and the optical parts for focusing are the
same.
The test stand for the composite fiber was designed under the mentioned conditions. Figure
7.2 shows the whole of this system. It is composed of objective lenses, a focusing system, a
composite fiber, a light source, a TV monitor, a CCD camera and its controller. The objective lens
head which includes the optical parts imitates the branch pipe welding/cutting nozzle, as shown in
Fig. 7 .3 . Figure 7.4 shows the focusing system. It consists of a CCD camera for observation
of images, an optical coupling for sharing the reflected images and laser transmission, focusing lenses
for laser and images, and so on.
Figure 7.5 shows the fabricated composite fiber and test stand. Two composite fibers were
fabricated to compare the difference in optical performance. Figure 7.6 shows the schematic view
of the composite fiber and Table 7.1 shows the specifications of each fiber. The two fibers are
basically the same structure but contain the different number of image fiber, which causes the
different viewing resolution.
- 4 5 -
JAERI-Tech 99-048
Table 7.1 The specifications of composite fiber
Item
Material
Length
Outer dia. of composite fiber
Max. allowable bending dia.
Type A (low resolution)
pure silica
1 m
about 1.0 mm
250 mm
Type B (high resolution)
<—
10m
about 2.0 mm
<-
Laser transmission
- core diameter
- clad diameter
0.52 mm
0.6 mm
0.7 mm
0.8 mm
Image transmission
- fiber diameter
- number of fibers
9 (im
3000 pixels
10 |o.m
15000 pixels
7-2. Observation test
In order to confirm the basic performance of the composite fiber and to verify the adequacy of
this system, observation tests were carried out using the fabricated composite fiber and test stand.
In the observation tests, the following objects were observed; (1) various lines with a different width,
(2) SS pipe connection before and after welding.
(1) Object: lines
Figure 7.7 shows the results of observation test for the lines. The width of lines are
0.01, 0.2 and 0.3 mm. In this test, the number of image fiber is 15000 pixels. Though
the quality of stationary picture is not good, each line can be recognized by the animated
picture.
(2) Object: SS pipe connection before and after welding
Figure 7.8 shows the results of observation tests, in case of SS pipe before and after
YAG laser welding. In this test, two types composite fibers are tested. Though the
quality of stationary picture is not good, each picture can be recognized by the animated
picture.
7-3. Conclusion
The composite fiber for combing the laser and images transmission has been developed for
precise positioning and monitoring so as to assure the quality of welding/cutting. The prototype
fiber was fabricated to confirm the resolution and to verify the adequacy of this system. From the
results of observation tests, the following results are obtained.
1) Though the further optimization is needed, the objective can be observed by the
composite fiber.
- 4 6 -
JAERI-Tech 99-048
2) A focus of images from the fiber are proportional to the distance between the objective
and the lenses. The characteristic of focusing can be used for positioning before
welding.
In this study, the function of the observation was tested using the fabricated composite fiber.
In the next step, the penetration test of the high power laser is needed for the YAG laser
welding/cutting. In addition, an image processing technique for the scattered laser light while
welding is also required to verify the quality assurance of YAG laser welding.
- 4 7 -
JAERI-Tech 99-048
8. Conclusions
The remote bore tools for the blanket cooling pipes have been successfully developed and the
advanced technologies have been demonstrated through the ITER R&D task. All tools and
technique can be adopted to pipe welding, cutting and welding inspection under the ITER in-vessel
environments. Each conclusion of this task is summarized bellow :
(1) Branch pipe welding/cutting tool
A YAG laser type processing head and traveling trucks have been successfully fabricated and
the applicability to the blanket branch pipe welding/cutting has been demonstrated. The following
conclusions are obtained:
1) The optimum conditions of welding speed and laser power is 0.5 m/min for 1100 W.
2) A maximum allowable gap for welding is to be around 0.5 mm without filler materials.
3) The optimum conditions of cutting speed and laser power is 0.8 m/min for 1000 W.
4) Rewelding of the laser cutting surface can be performed with keeping similar mechanical
properties to those of machining surface.
5) Welding/cutting in the various posture is available.
6) Repeat welding/cutting is possible at least by 5 times.
7) Inchworm type traveling mechanism shows the traveling speed of 0.5 m/min in the
manifold with bent and curved sections.
(2) Manifold welding/cutting tool
A YAG laser type processing head has been successfully fabricated and the applicability to the
blanket manifold welding/cutting has been demonstrated. Though the processing head is only
developed, traveling trucks which are developed for the branch pipe welding/cutting tool can be
adopted to this head. The following conclusions are obtained:
1) The initial gaps of 50 mm in the axial direction and 10 mm in the lateral direction can be
aligned using the clanmping mechanism for welding.
2) The allowable gaps for pipe welding without filler materials are 0.8 mm in the axial
direction and 2.0 mm in the lateral direction.
3) The optimum conditions of welding speed and laser power are 0.3 m/min for 3600 W.
4) The optimum conditions of cutting speed and laser power are 0.3 m/min for 3000 W.
(3) Branch pipe inspection tool
The non-destructive inspection tool for the welding pipe has been successfully fabricated and
the applicability to the blanket branch pipe inspection has been demonstrated. The following
conclusions are obtained:
1) The arrangement of EMAT is a letter of "V" (reflection technique) and the angle between
elements is 100 degree.
2) The EMAT can detect 10 % defect on a base metal and 20 % defect across a weld region.
- 4 8 -
JAERI-Tech 99-048
3) The traveling speed of the tool is faster than l.Om/min in the manifold with bent and
curved sections.
(4) Branch pipe leak detection tool
The leak detection method for the branch pipes is studied and basic characteristic tests of leak
detection are carried out. The results of these tests and consideration are summarized below:
1) A probe method using nude gauge with directional nozzle can detect a small leak and meet
the ITER requirement.
2) Sniffer method using helium leak detector shows a low detectability compared with the
probe method. However, the detectability can be improved by adopting a scanning
mechanism to the sniffer tube for survey around the welding joint and by optimizing the
position of the sniffer tube.
(5) Composite fiber for welding/cutting/observation
The prototype composite fiber was fabricated to confirm the resolution and to verify the
adequacy of this system. From the results of observation tests, the following conclusions are
obtained:
1) Though the quality of image is to be improved, the welding/cutting can be monitored by
the composite.
2) A focus of images from the fiber are proportional to the distance between the objective
and the lenses. The characteristic of focusing can be used for positioning before
welding.
- 4 9 -
JAERI-Tech 99-048
ACKNOWLEDGMENTS
The authors would like to express their sincere appreciation to Drs. M. Ohta, S. Matsuda and
H. Kishimoto for their continuous encouragement on this work. The contributions by the staffs of
department of ITER project and Toshiba Corp., Hitachi Corp., Mitsubishi Heavy Industry Corp.,
Ishikawajima Harima Heavy Industry Corp. and Fujikura Corp. are gratefully acknowledged.
REFERENCES
[1] S.Matsuda, et al: Proc. 13th Conf. on Plasma Physics and Controlled Nuclear Fusion Research,
(Washington, 1990) IAEA-CN-53/G-2-2.
[2] K.Shibanuma, T.Honda, K.Satoh, Y.Ohkawa, T.Terakado, et al: Remote Maintenance System
Design and Component Development for Fusion Experimental Reactor, Proc. 16th Sympo. on
Fusion Tech., Vol.2, pp.l317-1321(1990)
[3] K.Honda, Y.Makino, M.Kondoh, K.Shibanuma: Feasibility Study of Internal-Access Pipe
Welding/Cutting System for Fusion Experimental Reactor(FER), Proc.LASER'91,(1991)
[4] K.Oka, S.Kakudate, M.Nakahira, et al: Critical Element Development of Standard Components
for Pipe Welding/Cutting by CO2 laser, JAERI Tech 94-033 (1994)
[5] M.Nakahira, K.Oka, S.Kakudate, et al: Feasibility Study on YAG Laser System for Cooling Pipe
Maintenance, ITER Emergency Task Agreement JB-RH-1 (1993)
[6] K.Oka, M.Nakahira, S.Kakudate, et al: Development of Remote Bore Tools for Pipe
Welding/cutting by YAG Laser, JAERI Tech 96-035 (1996)
- 5 0 -
Vacuum vessel
Rail
io-i
Rail mountedvehicle typemanipulator
>enso
Fig.1.1 Schematic view of the blanket module maintenance
Tool insertion
Cooling pipes
in
en
I
Cross sectionof the blanket
Blanket modules
1
\ j^3
J
w
1. Cutting with the branchpipe welding/cutting tool
IC
2. Remove the blanketmodule by the manipulator
/ r{
>m•pa
5
3. Rewelding after new 4. Non-destructive inspection 5. Leak detection testblanket module set
Fig.2.1 Schematic view of the procedure of the branch pipe maintenancefrom the inside of manifold
enCo
We Id I n g / C u t t i n g I i n e
pa
I
Fig.2.2 Pipe layout of upper port area
1. Initial state Bio-shield 5. Manifold cutting and removal
Blanket manifold
8. Class 3 component installation 11. Cryostat and bio-shield recovery
Guard pipe
2. Top bio-shield removal 6. Lower guard pipe cutting and removal 9. Lower guard pipe installation and welding
Cryostat •.
/
>
3. Upper cryostat cover removal 7. Class 3 component removal 10. Manifold installation and welding,
and upper guard pipe recovery
4. Upper guard pipe cutting and removal
ZLL
Support
I
\Alignment cone
Manifold/
Fig.2.3 Schematic view ofthe procedure of the manifold replacement
en
•-uis—fa , | ,
I&
i
Fig.2.4 A cask design for the boor tools
Laser and power source
JAERI-Tech 99-048
The cask forthe blanket pipe maintenance
Fig.2.5 Cask layout for the blanket pipe maintenance(cross section)
- 5 6 -
JAERI-Tech 99-048
The cask forthe blanket pipe maintenance Laser and power source
Fig.2.6 Cask layout for the blanket pipe maintenance(top of view)
- 5 7 -
Nozzle Sleeve^
en00
WeSaing/Cutting head
Over all of the weldinq/cuttinq tool
Nozzle
Welding / cutting nozzle
Eddy currentsensor
Fixing mechanisiTij
YAG Laser Processinq Head
Slider shaft Traveling truck B
Traveling truck A Pushing pad
Traveling trucks
Head through bent pipe
Fig.3.1 The branch pipe welding/cutting tool
is00
CJl
so
Traveling truck B Traveling truck A Measurement truckFlexible tube
Main pipeProcessing head
5oCO<o
Fig.3.2 YAG laser welding/cutting system for the branch pipe
CTO
I
Assist gas
A
A5
Transmission tube
Optical fiber
A-A
Fig.3.3 Schematic view of the transmission tube
Ring ditchZ-axis positioning mechanism
|«_ g Z-axis air cylinder
Welding/cutting head
Centering drive motor
Fig.3.4 YAG laser welding/cutting head
VIEW E - E VIEW F
>
I
2oo
Fig. 3.5 (1) Measurement truck
CO
I
8 > L . _ .
i
i?s
I
CO
Fig.3.5 (2) Traveling truck
JAERI-Tech 99-048
Flexible tubePower & measurement truck
V n
Traveling truck B Traveling truck A Processing head
Confiquration of the branch pipe weldinq/cuttinq tool
Step 0. Initial position^ pp
Truck
Step 1. Fix [A] support[1L
R— 1 L —A Truck
Step 2. Move [A] slider — B - A—b Truck
Step 3. Fix [B] support — B - rv - A — ^ = Truck
Step 4. Release [A] support 4^=-L._R—L r~A"~ Truck
Step 5. Move [B] slider& Move [A] slider
R I Truck
Fig.3.6 Procedure of traveling
- 6 4 -
JAERI-Tech 99-048
3600
1 G G 0
t
l Winding equipment
Bend pipe 1
FlangeBend pipe 2
Straight pipe
Straight pipe jointed branch pipe
ooCD
Fig.3.7 (1) Mock-up test system
- 6 5 -
JAERI-Tech 99-048
fcV
(1) Cable winding equipment for the tool and manifolds
• ; lit
i ' ' I
(2) Appearance of the tool set
Fig.3.7 (2) Mock-up test system
- 6 6 -
JAERI-Tech 99-048
(3) Mock-up view of the laser processing
Fig.3.7 (3) Mock-up test system
- 6 7 -
JAERI-Tech 99-048
Fig 3.8 Location of the blanket modules
- 6 8 -
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
>sTH3-
Fig.3.9 (1) Results of the bead appearance test as a parameter of defocus
-1.0 mm 0 mm +1.0 mm +1.5 mm
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
ioo
Fig.3.9 (2) Results of the macroscopic test as a parameter of defocus
I
900 W 1000W 1100W
[Processing conditions] Welding speed : 0.5 m/min
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Defocus : +1 mm
Duty : 50 %
Weld joint: butt joint
iCOCO
Fig.3.10 (1) Results of the bead appearance test as a parameter of laser power
900 W 1000W 1100W
[Processing conditions] Welding speed : 0.5 m/min
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Defocus : +1 mm
Duty : 50 %
Weld joint: butt joint
pa
I
Fig.3.10 (2) Results of the macroscopic test as a parameter of laser power
0.4 m/min 0.5 m/min
C T i
0.6 m/min
[Processing conditions] Laser power: 1000 W Defocus : +1 mm
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm Weld joint: butt joint
Gap : 0 mm
Fig.3.11 (1) Results of the bead appearance test as a parameter of welding speed
55s
0.4 m/min 0.5 m/min
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
0.6 m/min
Defocus : +1 mm
Duty : 50 %
Weld joint: butt joint
8
Fig.3.11 (2) Results of the macroscopic test as a parameter of welding speed
0 mm 0.5 mm 1.0 mm
1H
8-
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Weld joint: butt joint
Welding speed : 0.5 m/min
Duty : 50 %
Fig.3.12 Results of the bead appearance test as a parameter of gap
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Fig.3.13 (1) Results of the macroscopic testas a parameter of 0 mm gap
- 7 6 -
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0.5 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Fig.3.13 (2) Results of the macroscopic testas a parameter of 0.5 mm gap
- 7 7 -
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 1.0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Fig.3.13 (3) Results of the macroscopic testas a parameter of 1.0 mm gap
- 7 8 -
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 1.5 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Fig.3.13 (4) Results of the macroscopic testas a parameter of 1.5 mm gap
- 7 9 -
00o
I
-1.0 mm 0 mm +1.0 mm
[Processing conditions] Laser power: 1000 W
Frequency: 40 Hz
Work distance : 2 mm
Cutting speed : 0.8 m/min
Duty : 50 %
>mpa
ls
Fig.3.14 (1) Results of the appearance test as a parameter of defocus
Defocus
I00
Manifoldside
Blanketmoduleside
-1.0 mm 0 mm +1.0 mm
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Cutting speed : 0.8 m/min
Duty : 50 %
5=0
i
Fig.3.14 (2) Results of the appearance test as a parameter of defocus
>
i
[Processing conditions] Laser power: 1000 W Cutting speed : 0.8 m/min
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm
Fig.3.14 (3) Results of the macroscopic test as a parameter of defocus
ooCO
900 W 1000 W 1100 W
[Processing conditions] Cutting speed : 0.8 m/min Defocus : +1.0 mm
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm
Fig.3.15 (1) Results of the appearance test as a parameter of laser power
Power
I00
Manifoldside
Blanketmoduleside
900 W 1000W 1100 W
[Processing conditions] Cutting speed : 0.8 m/min Defocus : +1.0 mm
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm
M
i£
Fig.3.15 (2) Results of the appearance test as a parameter of laser power
ooon
[Processing conditions] Cutting speed : 0.8 m/min Defocus :+1.0 mm
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm
so
i
Fig.3.15 (3) Results of the macroscopic test as a parameter of laser power
I00
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : +1.0 mm
Duty : 50 %
2
S
Fig.3.16 (1) Results of the appearance test as a parameter of cutting speed
IOO
Speed
Manifoldside
0.7 m/min
Blanketmoduleside
0.8 m/min 0.9 m/min
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : +1.0 mm
Duty : 50 %
5COco
Fig.3.16 (2) Results of the appearance test as a parameter of cutting speed
0000
0.7 m/min
• • • •0.8 m/min 0.9 m/min !
H|HH|
[Processing conditions] Laser power: 1000 W Defocus : +1.0 mm
Frequency : 40 Hz Duty : 50 %
Work distance :2 mm
i
Fig.3.16 (3) Results of the macroscopic test as a parameter of cutting speed
00to
(1) Bead appearance
[Processing conditions] Laser power: 1100 W
Frequency: 40 Hz
Work distance : 2 mm
Defocus : 0 mm
(2) Macroscopic observation
Welding speed : 0.5 m/min
Duty: 50 %
Weld joint .butt joint
Gap : 0 mm
iI
Fig.3.17 Result of the rewelding test
JAERI-Tech 99-048
(1) Setting angle of manifold : 28° (No.1 blanket)
(2) Setting angle of manifold : 83° (No.7 blanket)
(3) Setting angle of manifold : 8° (No.13 blanket)
[Processing conditions] Laser power: 1100 W Welding speed : 0.5 m/min
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm Weld joint: butt joint
Defocus : 0 mm Gap : 0 mm
Fig.3.18 Result of the bead appearance testin the various posture welding
- 9 0 -
JAERI-Tech 99-048
(1) Setting angle of manifold : 28° (No.1 blanket)
(2) Setting angle of manifold : 83° (No.7 blanket)
(3) Setting angle of manifold : 8° (No. 13 blanket)
[Processing conditions] Laser power: 1100 W Welding speed : 0.5 m/min
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm Weld joint: butt joint
Defocus : 0 mm Gap : 0 mm
Fig.3.19 Result of the liquid penetrant testin the various posture welding
- 9 1 -
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Gap : 0 mm
Manifold angle : 28° (No.1 blanket)
Fig.3.20 Result of the macroscopic testof the various posture weldingat position of No.1 blanket (28°)
- 9 2 -
JAERI-Tech 99-048
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Gap : 0 mm
Manifold angle : 83° (No.7 blanket)
Fig.3.21 Result of the macroscopic testof the various posture weldingat position of No.7 blanket (83°)
- 9 3 -
JAERI-Tech 99-048
Position 1
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Gap: 0 mm
Manifold angle : 8° (No. 13 blanket)
Fig.3.22 Result of the macroscopic testof the various posture weldingat position of No. 13 blanket (8°)
- 9 4 -
JAERI-Tech 99-048
Setting angle
Blanket No.1(28°)
Blanket No.7(83°)
Blanket No.13(8°)
c
lip
Cutting
iiIjiplllplilll•H
appearance
HBBB^S^BoBSMM^^^™|WHM^^^BwBBwl|Bn|B
iJJMSJMMMfc-MfcJ" J*-JHt>i WMJjjiljHUMMiMMWftaWManBea jaHLIJalSMMlMBSHBMMeMllllPllllll"jtlltMljM"MHlM8BIB|aMiaWWMa>iMIBMflei
H H H B H HSHWHHBBii
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : 0 mm
Welding speed : 0.8 m/min
Duty : 50 %
Weld joint: butt joint
Gap : 0 mm
Fig.3.23 Results of the appearance testin the various posture cutting
- 9 5 -
JAERI-Tech 99-048
Setting angle
Blanket No.1(28°)
Blanket No.7(83°)
Blanket No. 13(8°)
Cross section
[Processing conditions] Laser power: 1000 W
Frequency : 40 Hz
Work distance : 2 mm
Defocus : 0 mm
Welding speed : 0.8 m/min
Duty : 50 %
Weld joint: butt joint
Gap : 0 mm
Fig.3.24 Results of the macroscopic testin the various posture cutting
- 9 6 -
JAERI-Tech 99-048
c2 b2 a 2V I /
i
§ is
1!
4
<
• 4
1 • 4
•
* • 4
t •
» • 4
I |
»
i
(1) Measurement positions before welding
cl bl al a2 b2 c2V \ _
8 a
i i i
• • •. . .
• • »
• • •• • •
! I II !
±l^ 37.0 ^
42.0470
34.5-^ 39.5 T
44.5
(2) Measurement positions after welding
Fig.3.25 3-D measurement points of the branch pipe
- 9 7 -
JAERI-Tech 99-048
1.5
E 1
W
•% 0.52
nne
8?-0-5
o _«co '
- 1 . S
1.5
w
(0
L.<D
C
0.5
0 ,r
0)
M -0.5
O - 1CO '
-1.5
45 90 135 180 225 270
Angle of measuring position (degree)
(1) Manifold side
315 360
-—b2
31545 90 135 180 225 270
Angle of measuring posit ion (degree)
(2) Blanket module side
Fig.3.26 The change of the shrinkage quantityafter repeat welding (1 cycle)
360
JAERI-Tech 99-048
1.5
E 1
(0
•-1 0.52<0
§ 0 rs
O0)TO u s
O _1CO 1
-1.5
:r-i-*-J• • - * - • . -I
--'» . —«—-•—
- — b 1
—-»—«—
45 90 135 180 225 270
Angle of measuring position (degree)
(1) Manifold side
315 360
1.S
£ 1
wM 0.520)cc
0)
oCO
-0.5
-1
-1.5
— b2-*-c2
1
45 90 135 180 225 270
Angle of measuring position (degree)
(2) Blanket module side
315 360
Fig.3.27 The change of the shrinkage quantityafter repeat welding (2 cycle)
- 9 9 -
JAERI-Tech 99-048
1.5
E 1
CO
4 0.52
I °o
J>-0.5c
Xo <
CO " '
-1.5
- - * — * ". . - • - • • • • - <
_ _ • — • —— • • —
——«—»—— —«—• '
•—a1-—b1
—« » —•—•—• - • - • - • - •
» »
1.5
£ 1
^ 0.5
i oo
| - 0 . 5
c
O iCO " '
-1.5
45 90 135 180 225 270
Angle of measuring position (degree)
(1) Manifold side
315 360
— a2
-— b2-^-c2
0 45 90 135 180 225 270 315 360
Angle of measuring position (degree)
(2) Blanket module side
Fig.3.28 The change of the shrinkage quantityafter repeat welding (3 cycle)
- 1 0 0 -
JAERI-Tech 99-048
1.5
E
••i 0.52©
i o
^ " 0 . 5
o «co '
-1.5
• • — .,-m—* — *
: : : :
• • « »
45 90 135 180 225 270
Angle of measuring position (degree)
(1) Manifold side
315 360
1.5
E
=i 0.5(0
CC
8?-0.5:
oCO -1
-1.5
r *~T 'J :
- ^ - a 2
— b2
- * - c 2
45 90 135 180 225 270
Angle of measuring position (degree)
(2) Blanket module side
315 360
Fig.3.29 The change of the shrinkage quantityafter repeat welding (4 cycle)
- 1 0 1 -
JAERI-Tech 99-048
1.5
E 1
I 0.52V .
§ o
M AC
c
o -1
-1.5
- - * - -4- -i
. '•— - » — • ,
4 •
- ^ a 1
— b1
—«— i >
1.5
E 1EV)
••£ 0.52
i
^ - 0 . 5
c
-1.5
45 90 135 180 225 270
Angle of measuring position (degree)
(1) Manifold side
315 360
.r •f-T;y-=-j:.4-4-..i
— ^ i—: —"f = + -^
- ^ - a 2
- — b 2
- ^ - c 2
—* i zj
45 90 135 180 225 270
Angle of measuring position (degree)
(2) Blanket module side
315 360
Fig.3.30 The change of the shrinkage quantityafter repeat welding (5 cycle)
- 1 0 2 -
JAERI-Tech 99-048
2 cycle
4 cycle
3 cycle
5 cycle
[Processing conditions] Laser power: 1000 W Cutting speed : 0.8 m/min
Frequency : 40 Hz Duty : 50 %
Work distance : 2 mm Defocus : 0 mm
Fig.3.31 Results of the appearance testin the repeat cutting
- 1 0 3 -
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Defocus : 0 mmGap : 0 mm
Fig.3.32 (1) Results of the appearance and macroscopic tests in the repeat welding (1)
I
II—»
o
I
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Defocus : 0 mmGap : 0 mm
Fig.3.32 (2) Results of the appearance and macroscopic tests in the repeat welding (2)
JAERI-Tech 99-048
Appearance
Cross section
5 cycle
;i!«lfiiiiiiHiiiiiiiiii m •;
fl8B1BiBBH9B^BSB^B^^B^H^B^B^H^^«^raiCT^4MHWlWBB^BHHHBfl)BJ^B^^BJW^WB^Oj||pCffl»sSsSjip|^^
* p •llfpSfSfflls
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Defocus : 0 mm
Manifold angle : 83° (No.7 blanket)
Fig.3.33 Results of the appearance and macroscopic testin the repeat welding at the position of the No.7 blanket
- 1 0 6 -
o
Liquidpenetrant
testing(PT)
results
[Processing conditions] Laser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Defocus : 0 mm
5co
Manifold angle : 8° (No.13 blanket)
Fig.3.34 Results of the penetrant testing after the repeat weldingat position of the No. 13 blanket (8°)
o00
Liquidpenetrant
testing(PT)result
5 cycle
" llf^^HffiBIllilr lit
i «! W « |SQ <W <* *• '*
[Processing conditions]
isLaser power: 1100 W
Frequency : 40 Hz
Work distance : 2 mm
Gap : 0 mm
Welding speed : 0.5 m/min
Duty : 50 %
Weld joint: butt joint
Defocus : 0 mm
Manifold angle : 83° (No.7 blanket)
Fig.3.35 Results of the penetrant testing after the repeat weldingat position of the No.7 blanket (83°)
II—'o
I
Over view
itail A
Rlankflt manifnIH
Detail A
Fig. 4.1 Blanket Cool ing Manifold
I
iGuide ring (Alignment cone)
Alignment hook Air cylinder
Fiber (Dia. 1.0)
2 2 5 d e g ( T h e t a a x i s ) Mirror/ \_R axis motor\Lens\
O p t i c a l p a r t s
>
o
COCO
Theta axis motor
Fig. 4.2 Structual Design of Manifold Welding/Cutting Tool
>si
Tool Nozzle
Fig. 4.3 Welding/Cutting Tool for Blanket Manifold
Pipe Cutting Pipe Welding
1. Pipe clamping 1. Pipe clumping
to
I
2. Pipe cutting
Projection
2. Pipe alignment
3. Pipe welding
Fig. 4.4 Welding/Cutting Procedure
iCO
JAERI-Tech 99-048
Stepl:Travelling in the manifoldVacuum Vessel
Support Bio Shield
New pipeGuide ring (Alignment cone)
Projection
Step2Positioning of the tool and manifold cutting
Step3:Traveling in the manifold
Step4:Positioning of the tool and manifold cutting
Step5:Traveling in the manifold
Fig. 4.5 Cutting Operation Procedure
-113-
JAERI-Tech 99-048
Stepl:Travelling in the manifoldVacuum Vessel
Support Bio Shield
Projection Hew pipe
, Guide ring (Alignment cone)
.25, Tool
Step2-.Positioning of the tool
Step3:Alignment and welding of the manifold
Step4:Positioning of the tool
Step5'.Alignment and welding of the manifold
_J
Fig. 4.6 Welding Operation Procedure
-114-
en
I ioo
Fig. 4.7 Test Stand for Pipe Alignment
JAERI-Tech 99-048
Fig. 4.8 Result of cutting appearance
- 1 1 6 -
JAERI-Tech 99-048
1. Before alignment
He-Ne laser
Fixed pipe
Tool body
2. Under alignment
Flexible pipe
Fixed pipe
3. Completion of alignment
Flexible pipe
Fixed pipe
Flexible pipe
Fig. 4.9 Pipe Inner Surface by Image Fiber• 1 1 7 -
JAERI-Tech 99-048
il mm
Outside of pipe
Bead appearance
Inside of pipe
Flat position Overhead position
Cross section
Fig. 4.10 Results of welding bead appearanceand cross section
- 1 1 8 -
JAERI-Tech 99-048
welded pipe specimen (Material: SUS316L, 100AxS(\,.,scr; 3.6kW (CW) Welding speed: 0.3m/minshielding gas: N2,5OLVmin
Outside of pipe Inside of pipe
Bead appearance
Flat position Overhead position
Cross section
Fig. 4.11 Result of rewelding bead appearanceand cross section
- 1 1 9 -
JAERI-Tech 99-048
Tr. EMAT Weld region R e E M A T
Test piece
Ultra sonic wave Defect
(a) Transmission technique
Re. EMAT Tr. EMAT Weld region
Test piece
Ultra sonic wave Defect
(b) Tandem technique
Defect weld region\
Tr. EMAT
Re. EMAT
Ultra sonic wave
7
Test piece
(c) Reflection technique
Fig.5.1 EMAT arrangement methods
- 1 2 0 -
ICO
no slit
-O.D0
- . S 5 -
Tr. EMAT49mm
rrRe. EMAT
PipeT.P. t = 3mm
Inside 30%slit
.25
-.2
- .5
echo
Outside 30%slit
- . 2 5
Vecho
4 1 l i IS 3B 24 £ 3t -tu
Inside 20%sHt
c I I I I I I I I 1 I III I I 1 1 1•> a 13 is ao a-i fl 'A at .-4u
- . 2 5 -
Outside 20%slit
-O.ODl
- . 2 5 -
Ii
2oo
Fig.5.2 The results of non-destructive inspection test using the transmission technique
toDO
no slit
-Q.GU
4 a la is la a-t ia 3£ it, 4u
- . 2 5 -
Re.EMAT37min 13mm
Tr. EMAT
Pipe T.P. t = 3mm sHt
Inside 30%slit
. 2 5 -
-Q.QD
- . 2 5
. 5 ( J . 111,1 M i . l U
WWWecho
noise
I I i
Outside 30%slit
.25
- . 2 5 noiseecho
tus]
4 U 12 16 3D a-t id 'Ji 3b 40
>
255ocrCOCD
Fig.5.3 The results of non-destructive inspection test using the tandem technique
noslit Inside 30%slit c£ Edge (Plate T.P.,t=4mm)
- . D S l -
VI* VSMA
noise noise
I 55 53 63 B7 71'3s 39 43 47 SI 55 53 63 B7 71 75
-O.BI
-.«*-i n ' • • • • I'3S 39 43 47 51 5S 59 Ej BT 71 T5
Outside 30%slit c£ Edge (Pipe T.P.,outeide,fc=3mm)
Tr.EMAT
Re. EMAT
43 47 51 55 53 t l 67 71 5T
PipeT.P. t = 3mm3S 43 47 Si 55 53 E.J 6T 7 1
5
Fig.5.4 The results of non-destructive inspection test using the reflection technique
slit outside slit at no weld inside slit at no weld outside slit over weld inside slit over weld
testdirection
55mm
Defect
30%
55mm rr 56mm
VDefect Defect
56mm
Defect
thickness : 3 mmfrequency : 700 kHzwave : 4 periodsoutput : 15 Appgain : 80 dB
averaging : 10 times
20% impossible
transmission wave form
2/jS/div
3§-
10%impossible impossible
Noise Xrt rt , i> rt , A
-<**»••
5S—a—rt A .'h—rt—*K~
Fig.5.5 The results of non-destructive inspection test withthe prototype EMAT based on the reflection technique
Specifications of EMAT
FrequencyBeam AngleModeTemperature
: 700 kHz: 64.4 °: SH wave: 150 C°
Magnet- Material- Height- Width- Thickness- Number
: SmCo: 7.5 mm: 5.0 mm: 2.5 mm: 8 elements
Coil- Length- Width- Material
30 mm12 mmpolyamide based
Sensor arrangement Test piece
CJ1
Previous test !£?
defect
50200
L : Length
W : Width
This testoCO _rr
D : Depth
Artificial defect shape10%t slit1.5LxO.3WxO.3Dmm
20 %t slit3.0Lx0.3Wx0.6Dmm
30 %t slit4.5LxO.3WxO.9Dmm
50 %t slit7.5LxO.3Wx 1.5Dmm
Aspect ratio : 5
>
Soo
Fig.5.6 Angle test conditions for the reflection method
to
disposition of sensors
tranamit-raceivs angle26"
.9
transmit-receiveangle go*
braxunut-roooivoangle 90'
txananrit-receivBangle 100'
transmit-receiveangle no '
tranamit-receiva120*
SOKtalit 3OKtalit 20KtaUt lOStaUt no slit
Fig.5.7 The wave form of the angle test in the case of outside defect
5o
to
disposition of sensors
transmit-receive angle26*
tranamit-receiveangle go*
tranamit-receiveangle go'
tran»mit-recoiveangle 100'
transmit-receiveangle no*
transmit-ieoeiveangle 120'
6OStaUt 3OKtalit
3 if
20%tslit lOSt slit
Sf-T
no slit
s-
2oo
Fig.5.8 The wave form of the angle test in the case of inside defect
CO
1 5 -
1 0 -
5 "
l
o -
O''
/
i i i
y'
y'
y
- * * * *-***"^i
1
10 20 30 40
depth of slit (%)
(a) Inside defect
50
- - - f f l - - -
10 20 30
depth of slit W
(b) Outside defect
tranamit-receive
—o—,,,, ^. . . -Q. . . .
~"-A~~—
- - - f f i - - -
8
9
1 0
1 1
1 2
angle
0°
0°
0°
0°
0°
JAE
RI-T
ech
i
soo
Fig.5.9 (a) The comparison result of S/N level on sensor angle
CO 5 -
10 20 30 40 50
depth of slit
100°
......_ 26°
(a) Inside defect
10 20 30 40 50
depth of slit (%)
(b) Outside defect
.100°
26°
•pa
ICD
I
Fig.5.9 (b) The comparison result of S/N level on sensor angle
ooo
corner (100%t)
33
liftoff (mm)
Fig.5.10 The result of the lift-off test
It—'CO Connector Traveling truck No.2 Distance
sensorRotationpart
Inspectiontruck
Travelingtruck No.1
CO
oisOO
Fig.5.11 The non-destructive inspection tool with EMAT for the branch pipe
JAERI-Tech 99-048
(1) Appearance of the fabricated EMAT
magnet
magnet support plate casing2flexible print coilprotection panel casingl
-^.support plate
perspective magnetof magnet
cable-casingl
flexible print coilprotection panel
(2) Schematic view of the EMAT
Fig.5.12 Appearance of the fabricated EMATfor branch pipe inspection
- 1 3 2 -
00
I
252
A-A
Fig.5.13 Traveling truck
3ossoo
Strokeby motorStrokeby cylinder
EMAT
s
Fig.5.14 Inspection truck with EMAT
JAERI-Tech 99-048
252
Fig.5.15 Rotation part
- 1 3 5 -
JAERI-Tech 99-048
252
Fig.5.16 Distance sensor unit
- 1 3 6 -
JAERI-Tech 99-048
229
Fig.5.17 Connector unit
- 1 3 7 -
JAERI-Tech 99-048
AH
A - A
Fig.5.18 Connection part
- 1 3 8 -
JAERI-Tech 99-048
Top view
h ,. *
Back view Side view
(1) Appearance of the EMAT sensor on the pipe
C : inside,accross weld
A : inside,base metal EMAT
I IipeSpipe
D : outside,accross weld
weldregion
B : outside,base metal
(2) Position of the artificial defects
Fig.5.19 Appearance of the EMAT for setting inspection tests
- 1 3 9 -
oI
pa
I&I
2oo
Fig.5.20 Signal wave of the inspection tests with EMAT
JAERI-Tech 99-048
(1) Vacuum method
Vacuum ~" Detector
Permanent or temporary
tracer gas supply tube
Connection line
(2) Probe method
VacuumDetector
Permanent or temporary
tracer gas supply tube
Connection line
Probe (Ion-gauge)
(3) Sniffer method
Tracer gas under pressureDetector
Permanent or temporary
Sniffer tube
Connection line
Fig.6.1 Leak localization concept of branch pipe
- 1 4 1 -
JAERI-Tech 99-048
Fig.6.2. Outline of Leak detection process
NDT of pipe welding joint
Leak test of blanket modules connected to a cooling manifold(When a leak is defected)
Leak localization
- 1 4 2 -
coI
ELD]
He tankHead axial driving unit
N2 tankV4>
Vacuumpump unit
Axial direction range 660
Sniffer tube0.9mm dla.length: 25 m
SP
Manifold (100mm dla.)Branch pipe A, B (50mm dta)
2500
Ho
Fig.6.3. Structure of Leak detection test equipment
Leak test equipment controlle
so
II
2oo
Fiq.6.4 Appearance of Leak detection test equipment
JAERI-Tech 99-048
Plasma side
Blanch pipe
Fig.6.5. Blanket module cooling channel model
- 1 4 5 -
JAERI-Tech 99-048
Fig.6.6. Blanket module cooling channel equivalent circuit- 1 4 6 -
JAERI-Tech 99-048
.Steeping motor ,...<[._•luni/at ion gauqe .-• .. _- - ; " f fT ' ' " • * - "
Probe head appearance
OD=60.3
^•Branch pipe
Rod
lonization gauge
Probe head structure
Fig.6.7. Detection head partial model of Probe method
- 1 4 7 -
JAERI-Tech 99-048
00 4 6 8 10
D-(mm)
Fig.6.8. Directional nozzle size fixed graph
Relation between L (length of the tube) and D (diameter of the tube) in orderto make the value E (rate of leakage into the sensor out of whole leakage)maximum.
- 1 4 8 -
JAERI-Tech 99-048
Sniffer head appearance
Sniffer tube
Orifice
Sniffer head structure
Fig.6.9. Detection head partial model of Sniffer method
- 1 4 9 -
oI
He leakpositionQLHe
He gasLD Signal level
0
i
A pipe center |Tube head positionB pipe center Scan area of manif
Fiq.6.10. Leak ditection concept bv Sniffer method
JAERI-Tech 99-048
Fiq.6.11. Schematic diaaram of Probe method
Vacuum PumGate valve open
) m g r - Manifol
Probe
Stroke x50mm
' Orifice
Leak point1A, 2 A
Radial direction
Fig.6.12. Schematic diaaram of Sniffer method
••• Carrier gas install Flow
Rough pumping
Gate valve closed
Manifol
Sniffer tube-
Stroke5Qmm_i.
• Orifice
Branch pipeleak point
1A, 2A
Radial directionAxial direction Max.660mm
- 1 5 1 -
JAERI-Tech 99-048
« 5x1 (T4
n. oovo. oov
1X10"4 -=
5x10"
0.00V0.OOV
1X10"
Leak test start after 1 minuet
Dammy leak point: 1A, Leak rate: Z4x10'7Pa-m3/s HeRadial direction scan speed: 0.1m/min
Leak point(45mm)
I
Probe
t Scan startoriqin(Omm)Leak valve open a v '
tPipe
Scan endend position(50mm)
Measurement time(sec)201). Os
Leak test start after 15 minuets
Dammy leak point: 1 A, Leak rate: 2.4x10"7Pa-m3/s HeRadial direction scan speed: 0.1m/min
Leak point(45mm)
Probe /
/
Scan startorigin(0mm)
Scan endendposition(50mm)
Pipe
Measurement time(sec)
Fig.6.13. Results chart by Probe method
- 1 5 2 -
JAERI-Tech 99-048
Test condition
Leak position:Scanning direction:Scanning speed:Carrier gas (N2) flow rate:Pipe inner pressure:
He leak rate:Time constant (delay time):
Branch pipe 1AManifold axial [Origin - End (660mm) - Origin]200 mm/min.11 l/min.9.3 kPa2x10'4Pa*m3/sec65 sec (due to 25m long tube)
Fig.6.14. Results chart by Sniffer method
- 1 5 3 -
JAERI-Tech 99-048
Test condition
Leak position:Scanning direction:Scanning speed:Carrier gas (N2) flow rate:Pipe inner pressure:
He leak rate:Time constant (delay time):
Branch pipe 1A + 2AManifold axial [Origin - End (660mm) - Origin]200 mm/min.11 l/min.
9.3 kPa8x10"4Pa*m3/sec65 sec (due to 25m long tube)
Fig.6.15. Results chart by Sniffer method
- 1 5 4 -
Fiber for image transmission
enon
Tube for cover
Fiber for laser transmission
A-A
i
Fig.7.1 The conceptual design of the composite fiber
Ien
TV monitor
Focusing system YAG laserComposite fiber
Objective lenses
Optical fiber for light guide
Xe light source
Camera controller
wso
i
Fig.7.2 The test stand for the composite fiber
Mirror
Composite fiber
II—>
en
Coliimate lenses
Objective lenses
ii
£oo
Mirror
Fig.7.3 The objective lenses for the composite fiber
Fixing table
CCD camera
YAG laser
Laser focusing lens
Zoom lens
Laser mirrorLaser focusing lens
Mirror adjustmentmechanism
Composite fiber
jo
iI
sCD
Fig.7.4 The optical stage for focusing and sharing of laser and image transmission
enCO
(a) Full view of the test stand
(b) Objective lenses
55ocoCO
I
(c) Optical stage
Fig.7.5 The fabricated test stand for the composite fiber
JAERI-Tech 99-048
SS flexible tubeEpoxy-acrilate
CO
CO
Optical fiber for laser transmission(pure silica core)
O i r
CD
O
CM CD
Jacket tube(silica glass) Optical fiber for Image
transmission(pure silica glass, 3000 pixels)
(a) Composite fiber A
SS flexible tubeEpoxy-acrilate Optical fiber for laser transmission
(pure silica core)
Jacket tube(silica glass) Optical fiber for Image
transmission(pure silica glass, 15000 pixels)
(b) Composite fiber B
Fig.7.6 The schematic view of the composite fibers
- 1 6 0 -
JAERI-Tech 99-048
Image fiber
Laser fiber
Line
(a) Line width : 0.01 mm
(b) Line width : 0.2 mm
(c) Line width : 0.3 mm
Fig.7.7 The results of the observation test: lines(image fiber of 15000 pixels)
- 1 6 1 -
JAERI-Tech 99-048
(1) normal view (2) SS pipe connection
(a) Image fiber: 3000 pixels
(1) SS pipe connection before welding (2) SS pipe connection after welding
(b) Image fiber: 15000 pixels
Fig.7.8 The results of the observation test: SS pipe
- 1 6 2 -
JAERI-Tech 99-048
Appendix-A
YAG Laser Welding/cutting Characteristics
A-l. Welding/Cutting Tests with Dual YAG laser
Figure A-l . 1 shows the dual YAG laser system utilized for the tests. This system is composed
of a 1.8 kW (CW) and a 1 kW (PW) laser sources, three optical fibers and an optical connector. Two
optical fibers are used for the transmission of 1.8 kW and 1 kW laser, respectively. The core diameter
and length of optical fiber for 1.8 kW laser are 0.6 mm and 200 m. The core diameter and length of
optical fiber for 1 kW laser are 0.6 mm and 5m. These fibers are combined at the optical connector.
The optical fiber with a core diameter of 1.2 mm and a length of 5m is used for the transmission of
combined laser between the optical connector and welding/cutting nozzle.
A-l-1. Basic Welding Test
In this test, the welding conditions were surveyed using SS316L plate with a thickness of 6.0 mm
as parameters of defocus, laser power, welding speed, welding position and gap, as listed below.
Defocus : -1.6, -1.2, -0.8, -0.4, 0, 0.4, 0.8, 1.2, 1.6 mm
Total laser power : 1400 W (856 W (CW)+544 W (PW))
1600 W (978 W (CW)+622 W (PW))
1800 W (1100 W (CW)+700 W (PW))
Duty : 50% (CW), 29% (PW)
Welding speed : 0.2, 0.4, 1.0, 1.5 m/min
Welding position : Flat position, Horizontal position
Gap quantity : 0, 0.2, 0.4, 0.6 mm
Shield gas : Nitrogen
As an additional test, the in-process monitoring was performed to observe the welding operation
state.
A-l-1-1. Dependency of defocus, laser power and welding speed
The dependency of defocus, laser power and welding speed on the welding quality was
investigated. In this test, the butt weld without gaps was adopted. The following tests were
performed for the qualification; (1 )appearance and macroscopic test and (2)radiographic test (RT).
(l)Appearance and macroscopic tests
Figure A-1.2 shows the results of bead appearance and macroscopic test as a parameter of
defocus. The quantities of weld metal with a defocus of -0.4 mm were observed. Figure A- l . 3
shows the results of bead appearance and macroscopic test as a parameter of laser power. In case of a
defocus of -0.4 mm and a welding speed of 0.4 m/min, the quantities of weld metal was observed
under a condition of 1800W laser power. Figure A- l .4 shows the results of bead appearance and
macroscopic test as a parameter of welding speed. In the case of a laser power of 1800W and a
defocus of -0.4 mm, the quantities of weld metal was observed under a condition of 0.2 m/min
- 1 6 3 -
JAERI-Tech 99-048
welding speed. The distortion of welded plate became larger in proportion to the decrease of a
welding speed.
(2)Radiographic test (RT)
All samples satisfied the RT regulation (1st grade).
A-l-1-2. Dependency of welding position
The comparison of welding quality on welding position which are flat position and horizontal
position, was performed. The welding test conditions are 1.8 kW laser power, 0.4 m/min welding
speed and -0.4 mm defocus. In addition, the butt weld without gaps was adopted. The following tests
were performed for the quality; (l)appearance and macroscopic test, and (2)radiographic test (RT).
(l)Appearance and macroscopic tests
Figure A-1.5 shows the results of bead appearance and macroscopic test for the horizontal
position. The weld metal quantity was almost same in all samples.
(2)Radiographic test (RT)
All samples satisfied the RT regulation (1st grade).
A-l-1-3. Dependency of gap
The dependency of gap on welding quality were investigated as parameters of gaps and filler wire.
The gap ranging from 0 to 0.4 mm were examined under the conditions of 1870 W laser power, 0.25
m/min welding speed and -0.4 mm defocus. The gap ranging from 0.4 to 0.6 mm were also
examined using filler wire. The following tests were performed for the quality; (l)bead appearance
and macroscopic test, (2)radiographic test (RT) and (3)tensile test.
(l)Bead appearance and macroscopic test
Figure A-l . 6 shows the results of bead appearance and macroscopic test under the conditions of
0, 0.2 and 0.4 mm gaps without filler wire. Good penetrations were obtained in all samples.
However the under cut became larger in proportion to the increase of gap. Figure A-1.7 shows the
results of bead appearance and macroscopic test in case of 0.4 and 0.6 mm gaps with filler wire. The
under cut became smaller than the gap welding without filler wire. Good penetration in case of 0.4
mm was not obtained in spite of good penetration in case of 0.6 mm gap.
(2)Radiographic test (RT)
All samples except case of 0.4 mm gap welding with filler wire satisfied the RT regulation (1st
grade).
(3)Tensile test
Table A-l . 1 shows the summaries of the tensile test results. The tensile strength of all samples
were stronger than the base metal of stainless steel.
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JAERI-Tech 99-048
Table A-1.1 Results of tensile strength tests
Gap (mm)
0
0.2
0.4
Base metal
Tensile strength (MPa)
620, 620
607, 630
617,615
602
A-l-1-4. Availability of in-process monitoring
In this test, the availability of welding operation control by the in-process monitoring which means
the observation of luminous intensity, was investigated using optical fiber. The luminous intensity
changes in proportion to the changes of defocus, laser power and welding speed. The test result
shows that the change of defocus, laser power and welding speed can be detected by the in-process
monitoring.
A-1-1-5. Summary of welding test
1) Optimum welding conditions
Optimum conditions for SS316L plate with thickness of 6.0 mm using dual YAG laser are as
follows:
: 1800W (1100 W (CW)+700 W (PW))
: 50% (CW), 29% (PW)
: 0.4 m/min
: -0.4 mm
: Nitrogen
Total laser power
Duty
Welding speed
Defocus
Shield gas
2) Allowable gap
A maximum allowable gap with filler wire is considered about 0.6 mm or more.
3) In-process monitoring
The changes of defocus, laser power and welding speed can be detected by the observation of
luminous intensity in the welding operation.
A-l-2. Basic Cutting Test
In this test, the cutting conditions were investigated using SS316L plate with a thickness of 6 mm
as parameters of defocus, laser power, cutting speed and cutting position as listed below.
Defocus : -1.4, -0.9, -0.4, 0, 0.1, 0.6 mm
Total laser power : 1000 W, 1250 W, 1500 W
Cutting speed : 0.1 to 0.4 m/min
Cutting position : Flat position, Horizontal position
Assist gas : Nitrogen (5 kgf/cm2)
As an additional test, the in-process monitoring was performed to observe the cutting operation
- 1 6 5 -
JAERI-Tech 99-048
state.
A-l-2-1. Dependency ofdefocus, laser power and cutting speed
The dependency ofdefocus, laser power and cutting speed on the cutting quality were investigated.
The following tests were performed for the quality; (l)cutting appearance and (2)roughness of
surface.
(1) Cutting appearance
Figure A-1.8 shows the results of cutting appearance as a parameter of defocus. In this test, the
defocus ranging from -1.4 to 0.6 mm were examined under the conditions of 1250 W laser power
and 0.2 m/min cutting speed. The 6.0 mm thickness plate cutting with any defocus were possible.
The attachment of dross was observed in all samples. Figure A-1.9, 10 and 11 show the results
of cutting appearance as parameters of laser power and cutting speed under the condition of -0.4 mm
defocus. The 6.0 mm thickness plate cutting with any laser power were possible in spite of the dross
attachments on the back surface of all samples.
(2) Roughness of surface
Figure A-1.9, 10 and 11 show the results of surface roughness. The surface roughness
became smaller in proportion to the decrease of cutting speed and the increase of laser power.
A-l-2-2. Dependency of cutting position
In this test, the cutting quality with two cutting positions which are flat position and horizontal
position, were compared under the conditions of 1250 W laser power and 0.2 m/min cutting speed.
The following tests were performed for the quality; (l)cutting appearance and (2)surface roughness.
(l)Cutting appearance
Figure A-1.12 shows the results of cutting appearance by horizontal position. The cutting
quality by horizontal position was same as the flat position.
(2)Surface roughness
Figure A-1.12 shows the results of surface roughness by the horizontal position. The surface
roughness was same as flat position.
A-l-2-3. Availability of in-process monitoring
In this test, the availability of in-process monitoring by the observation of luminous intensity was
investigated. The luminous was not observed when the cutting was performed perfectly, while the
luminous was observed when the plate cutting could not be performed perfectly.
A-l-2-4. Summary of cutting test
(l)Cutting ability
The SS316L plate with a thickness of 6.0 mm can be cut under the conditions of 1000 W laser
power, 0.2 m/min cutting speed and -0.4 m defocus. But the dross attachment on cutting surface can
not be avoided.
(2) In-process monitoring
- 1 6 6 -
JAERI-Tech 99-048
The cutting results are estimated to be detected by the observation of luminous.
A-l-3. Re-welding Test
The re-welding test was performed in order to clarify the re-welding ability without machining
under the following conditions. In this test, the dross was removed from the cutting surface before
welding. The re-welding was performed twice and the butt weld without gap was adopted. The bead
appearance, macroscopic test, radiographic test (RT) and tensile strength test were performed for
welding quality.
l)Cutting conditions
Laser power
Cutting speed
Defocus
Assist gas
: 1250 W (650 W (CW)+600 W (PW))
: 0.2 m/min
: -0.4 mm
: Nitrogen, 5 kgf/cm2
2)Welding conditions
Laser power
Cutting speed
Defocus
Shield gas
1870 W (1110 W (CW)+760 W (PW))
0.25 m/min
-0.4 mm
Nitrogen
(l)Bead appearance, macroscopic test and radiographic test
Figure A - l . 13 shows the results of bead appearance and macroscopic test. All samples had good
bead appearances and satisfied the RT regulation (1st grade), but the organization that differ from
normal weld metal was observed at the center of bead.
(2)Tensile strength test
Table A -1 .2 shows the results of tensile strength test. The tensile strength of weld metal became
lower than the base metal due to the oxidation or nitride.
Table A-1.2 Results of tensile test
Gap (mm)
0.4
0.6
Base metal
Tensile strength (MPa)
612,615
608,617
602
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JAERI-Tech 99-048
A-2. Welding/Cutting Tests with High Power YAG laser
Basic welding/cutting tests using SS316L plate with a thickness of 7.6 mm were performed in
order to clarify the characteristics of high power YAG laser. Figure A-2.1 shows the high power
YAG laser system utilized for the tests. This system is composed of industrial 4 kW laser source and
an optical fiber with a core diameter of 1.0 mm and a length of about 10 m.
A-2-1. Basic Welding Test
In this test, the welding conditions were investigated using SS316L plate with a thickness of 7.6
mm as parameters of defocus, laser power, welding speed and gaps, as listed below.
Defocus : -3, -2, -1 , 0, 1 mm
Laser power : 3.4, 3.6, 3.8 kW
Welding speed : 0.2, 0.3, 0.4, 0.5 m/min
Gaps :0 ,0 .4 ,0 .8 ,1 .2 ,1 .4 mm
Assist gas : Nitrogen, 70 1/min
A-2-1-1. Dependency of defocus, laser power and welding speed
In this test, the dependency of defocus, laser power and welding speed on the welding quality were
investigated. The following tests were performed for the quality; (1) macroscopic test and
(2)microscopic test.
(l)Macroscopic test
Figure A-2.2 shows the results of macroscopic test as a parameter of defocus. In this test, the
defocus ranging from -3 to 1 mm were examined under the conditions of 3.8 kW laser power and 0.3
m/min welding speed. In the case of -1 or -2 mm defocus, the quantities of weld metal were
observed. Figure A-2.3 shows the results of macroscopic test as parameters of laser power and
welding speed under the condition of -1 mm defocus. The conditions of 3.6 kW laser power and 0.3
m/min welding speed were the optimum conditions for the welding of plate with a thickness of 7.6
mm.
(2)Microscopic test
Figure A-2.4 shows the results of microscopic test under the optimum conditions for welding of
plate with a thickness of 7.6 mm as listed below;
Laser power : 3.6 kW (CW)
Welding speed : 0.3 m/min
Defocus : -1 mm
Assist gas : Nitrogen, 70 1/min
No welding defect could be observed.
A-2-1-2. Dependency of gap and mismatch
In this test, the welding quality were investigated as a parameter of gaps ranging from 0 to 1.4 mm.
The gap welding were examined under the optimum conditions as mentioned above. The following
tests were performed for the quality; (l)bead appearance and macroscopic test and (2)tensile strength,
- 1 6 8 -
JAERI-Tech 99-048
elongation and fatigue strength.
(l)Bead appearance and macroscopic test
Figure A-2.5 shows the results of bead appearance and macroscopic test as a parameter of gaps.
The welding of gap up to 0.8 mm were possible without using filler wire. Figure A-2.6 shows the
results of bead appearance and macroscopic test as parameters of gaps and feeding rate of filler wire
with a diameter of 1.2 mm. The gap welding up to 1.2 mm using filler wire were possible, but the
under cut became larger in proportion to the increase of gap.
Figure A-2.7 shows the results of bead appearance and macroscopic test as a parameter of gap
using inter layer metal, with a thickness of 0.8 mm and a height of 9.1 mm, attached to the edge of
plate. The gap welding up to 1.2 mm was possible, but the under cut was larger than one of gap
welding using filler wire. Figure A-2.8 shows the results of bead appearance and macroscopic test
in the case of 2 mm mismatch. In this test, the welding ability with mismatch of 2 and 3 mm were
investigated. As the results, the mismatch welding up to 2 mm was possible without filler wire.
(2)Tensile strength, elongation and fatigue strength
Table A-2.1 shows the results of tensile strength and elongation for gap welding without filler
wire. The tensile strength and elongation deteriorated in proportion to the increase of gap. Figure A-
2.9 shows the results of fatigue strength in the case of the welding without filler wire. In this figure,
ASME Jaske & OiDonell Curve for stainless steel and master curve for stainless steel are shown in
order to compare with the curve of YAG laser welding. The fatigue strength of YAG laser welding
are estimated to be as same as one of TIG welding.
Table A-2.1 Results of tensile and elongation test
Gap (mm)
0
0.4
0.8
1.2
Base metal
Tensile strength (MPa)
568, 565
560 , 564 , 550
541 , 544 , 538
515 ,522 ,528
576
Elongation (%)
51.2,50.8
45.8,43.8,45.2
35.4,36.4,36.6
34.4 , 34.2 , 34.0
55
A-2-1-3. Summary of welding tests
(l)Optimum welding conditions
Optimum welding conditions for SS316L plate with a thickness of 7.6 mm using high power YAG
laser are as follows.
Laser power :3.6kW(CW)
Welding speed : 3 m/min
Defocus : -1 mm
Stand off : 5 mm
Assist gas : Nitrogen, 701/min
(2)Allowable gap and mismatch
169-
JAERI-Tech 99-048
A maximum allowable gap and mismatch without filler wire is up to 0.8 mm and 2 mm,
respectively.
A-2-2. Basic Cutting Test
In this test, the cutting conditions have been investigated using SS316L plate with a thickness of
7.6 mm. This test was performed as parameters of laser oscillation type (continuous wave or pulse
wave), laser power, cutting speed and assist gas flow rate, as listed below.
Laser oscillation type : Continuous Wave (CW), Pulse Wave (PW)
Laser power : 3.2, 3.6 kW (CW), 6 kW as peak power (PW)
Cutting speed : 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 m/min
Assist flow rate gas : Nitrogen; 125, 150, 175 1/min
Defocus : 0 mm
Stand off : 1 mm
A-2-2-1. Dependency of laser oscillation type and laser power
In this test, the dependency of laser oscillation type and laser power on the cutting quality were
investigated. This test was examined as parameters of 3.2 kW continuous wave, 3.6 kW continuous
wave and 6 kW peak power of pulse wave under the conditions of 0.4 m/min cutting speed and 175
1/min assist gas flow rate. The following tests were performed for cutting quality; (l)cutting surface,
(2)macroscopic test, (3)surface roughness, (4)kerf width, (5)bevel angle, (6)dross quantity and
(7)spatter quantity.
(l)Cutting surface
Figure A-2.10 shows the results of cutting surface as parameters of laser oscillation type and
laser power. The oxidation was observed on cutting surface in the cases of pulse wave and 3.2 kW
continuous wave.
(2)Macroscopic test
This test was performed under the cutting speed of 0.4 m/min. Figure A-2.11 shows the results
of macroscopic test. The results of all samples were almost same and the melted metal was observed
on cutting surface.
(3)Surface roughness
Figure A-2.12 shows the results that the cutting surface using 3.2 kW CW were rougher than
PW and 3.6 kW CW. In addition, the lower part on cutting surface in all samples were rougher than
upper part.
(4)Kerf width
This test was performed under the cutting speed of 0.4 m/min with PW, 0.6 m/min with 3.2 kW
CW and 0.6 m/min with 3.6 kW CW, respectively. Figure A-2.13 shows the results that the kerf
width in the case of PW was approximately 0.94 mm, and kerf width in the case of 3.6 kW CW was
approximately 1.01 mm.
(5)Bevel angle
This test was performed under the cutting speed of 0.4 m/min with PW, 0.6 m/min with 3.2 kW
170-
JAERI-Tech 99-048
CW and 0.6 m/min with 3.6 kW CW, respectively. Figure A-2.14 shows the results that the bevel
angle in the case of PW was approximately 2 degree.
(6)Dross quantity
This test was performed under the cutting speed of 0.4 m/min with PW, 0.6 m/min with 3.2 kW
CW and 0.6 m/min with 3.6 kW CW, respectively. Figure A -2.15 shows the test results.
(7)Spatter quantity
This test was performed under the cutting speed of 0.4 m/min with PW, 0.6 m/min with 3.2 kW
CW and 0.6 m/min with 3.6 kW CW, respectively. Figure A -2.16 shows the test results.
A-2-2-2. Dependency of cutting speed and assist gas flow rate
In this test, the dependency of cutting speed and assist gas flow rate on the cutting quality were
investigated. This test was examined as parameters of the cutting speed ranging from 0.3 to 0.8
m/min and assist gas flow rate ranging from 125 to 175 1/min using 3.6 kW (CW) laser power. The
following tests were performed for cutting quality; (l)cutting surface, (2)macroscopic test, (3)surface
roughness, (4)kerf width, (5)bevel angle, (6)dross quantity and (7)spatter quantity.
(l)Cutting surface
Figure A-2.17 shows the results of cutting surface as a parameter of cutting speed. The cutting
surface became rougher in proportion to the decrease of cutting speed, and the cutting of 7.6 mm
thickness plate was impossible in the cases of over 0.8 m/min cutting speed. The optimum cutting
speed was approximately 0.6 to 0.7 m/min. Figure A-2.18 shows the results as a parameter of
assist gas flow rate under the condition of 0.7 m/min cutting speed. The increase of dross in
proportion to the decrease of flow rate was observed.
(2)Macroscopic test
Figure A-2.19 shows the results of macroscopic test as a parameter of cutting speed. The width
of melted metal at the lower part on cutting surface became smaller in proportion to the increase of
cutting speed. Figure A-2.20 shows the results as a parameter of assist gas flow rate. As
mentioned above, the increase of dross in proportion to the decrease of flow rate was observed.
(3)Surface roughness
In this test, the surface roughness were measured. Figure A-2.21 shows the results of cutting
surface as a parameter of cutting speed. In the case of 0.6 m/min cutting speed, the surface was
smoothest. Figure A-2.22 shows the results as a parameter of assist gas flow rate under the
condition of 0.7 m/min cutting speed. The surface at 3.5 mm depth from plate surface became
smoother in proportion to the increase of flow rate. However the changes of surface roughness at 0.5
and 6.5 mm depth from plate surface were not observed in spite of the change of flow rate.
(4)Kerf width
Figure A-2.23 shows the results of kerf width as a parameter of cutting speed. Kerf width did
not change in spite of the increase of cutting speed and it was approximately 1.0 mm. Figure A-
2.24 shows the results as a parameter of assist gas flow rate. This test was performed under the
condition of 0.7 m/min. The increase of kerf width in proportion to the increase of flow rate was
observed.
- 1 7 1 -
JAERI-Tech 99-048
(5)Bevel angle
Figure A-2.25 shows the results of bevel angle as a parameter of cutting speed. Bevel angle did
not change in spite of the increase of cutting speed. Figure A-2.26 shows the results of bevel angle
as a parameter of assist gas flow rate. This test was performed under the condition of 0.7 m/min. The
decrease of bevel angle in proportion to the increase of flow rate was observed.
(6)Dross quantity
Figure A-2.27 shows the results of dross quantity as a parameter of cutting speed. The dross
quantity increased in proportion to the increase of cutting speed. Figure A-2.28 shows the results
as a parameter of assist gas flow rate under the condition of 0.7 m/min cutting speed. The dross
quantity decreased in proportion to the increase of gas flow rate.
(7)Spatter quantity
Figure A-2.29 shows the results of spatter quantity as a parameter of cutting speed. The spatter
quantity decreased in proportion to the increase of cutting speed. Figure A-2.30 shows the results
as a parameter of assist gas flow rate under the condition of 0.7 m/min cutting speed. The spatter
quantity increased in proportion to the increase of assist gas flow rate.
A-2-2-3. Summary of cutting tests
(l)Optimum cutting conditions
Optimum cutting conditions using SS316L plate with a thickness of 7.6 mm are as follows;
Laser power : 3.6 kW
Oscillation type : Continuous wave
Cutting speed : 0.6 m/min
Defocus : 0 mm
Stand off : 1 mm
Assist gas : Nitrogen, 175 1/min
(2)Cutting quality
Cutting quality is as follows under the optimum cutting condition, as mentioned above.
Surface roughness : 0.17 mm
Kerf width : 1 mm
Bevel angle : 3 degree
Dross quantity : 0.7E-2 g/mm
Spatter quantity : 4.0E-2 g/mm
A-2-3. Re-welding Test
In this test, re-welding ability was investigated using high power YAG laser under the optimum
cutting and welding conditions. This test was adopted butt welding without gaps and machining. The
microscopic test, radiographic test (RT) and tensile strength/ elongation test were examined for the re-
welding quality.
l)0ptimum cutting condition
Laser power : 3.6 kW
- 1 7 2 -
JAERI-Tech 99-048
Laser oscillation type : Continuous wave
Cutting speed : 0.6 m/min
Defocus : 0 mm
Stand off : 1 mm
Assist gas : Nitrogen, 175 1/min
2)Optimum welding condition
Laser power : 3.6 kW
Laser oscillation type : Continuous wave
Welding speed : 0.3 m/min
Defocus : -1 mm
Assist gas : Nitrogen, 70 1/min
(l)Microscopic test and radiographic test (RT)
Figure A-2.31 shows the results of microscopic test. Good penetration and organization were
observed, and no welding defect could be observed.
(2)Tensile strength and elongation test
The tensile strength and elongation test were 98.3% and 80.7% as compared with base metal.
- 1 7 3 -
JAERI-Tech 99-048
a)Laser head
b)Monitor
Fig.A-1.1 Dual YAG laser system
- 1 7 4 -
JAERI-Tech 99-048
Welding conditions Defocus(mm)
Cross section Bead appearance
Total powerCW powerDutyPW powerDuty
Welding speedAssist gasWelding joint:
800W489W50%31IW29%0.4m/minNitrogenButt
-1.6
-1.2
-0.8
-0.4
0
0.4
0.8
1.2
1.6
ir
• ^ ^ ^ ^
Fig.A-1.2 Bead appearance and macroscopic observation as a parameter of defocus
-175-
Welding condition Laser power Bead appearance MacroscopicobservatI on
Welding speedDefocusAssist gasWelding joint
:0.4 m/min:-0.4 mm:Nitrogen:Butt
Total:1800WCW:1100WPW:700W
Total:1600WCW:978WPW:622W
Total:1400WCW:856WPW:544W
3s
Fig.A-1.3 Bead appearance and macroscopic observation as a parameter of laser po
Welding conditions
Total powerCW powerDutyPW powerDuty
DefocusShield gasWelding joint
:1800W:1100W:50%:700W:29%:-0.4 mm:Nitrogen:Butt
Welding speed(m/m i n)0.2
0.4
1.5
Bead appearance Macroscopicobservation
5oCO«o
Fig.A-1.4 Bead appearance and macroscopic observation as a parameter of welding speed
Welding condition
Total powerCW powerDutyPW powerDuty
Welding speedDefocusAssist gasWelding jo int
:1800W:1100W:50%:700W:29%:0.4 m/min:-0.4 mm:Nitrogen:Butt
Bead appearance Macroscop i cobservat i on
trCOCO
I
oo
Fig.A-1.5 Bead appearance and macroscopic observation with horizontal position
JAERI-Tech 99-048
Q.
H—
oo
205Q.
03
.2
DISCLAIMER
Portions of this document may beillegible in electronic image products.Images are produced from the best
available original document.
Welding conditions Gap(mm)
Bead appearanceFront sur face Back sur face
Macroscopicobservation
ooo
I
Total powerCW powerDutyPW powerDuty
Welding speedDefocusShield gasWelding jo in t
M870W 0.4
:50%:760W:29%:0.25 m/min: -0 .4 mm:N i trogen:Butt
0.6 ii
soo
Fig.A-1.7 Bead appearance and macroscopic observation by gap welding with filler wire
Cutting conditions Defocus(mm) Front surface
Cutting surfaceBack surface Cross section
Total power :1250WCW power :650WDuty :50%PW power :600WDuty :29%
Cutting speed:0.2 m/minAssist gas :Nitrogen
0.6
0.1
-0.4
-0.9
-1.4
11 ill
>
18
Fig.A-1.8 Cutting surface as a parameter of defocus
Total power :1000WCW power :400WDuty :50%PW power :600WDuty :29%
Defocus :-0.4 mmAssist gas :Nitrogen
Cutting conditions Cutting speed(m/min) Front surface
Cutting surfaceBack surface Cross section
Roughness(um)
00to
0.1
0.15
0.2
0.25
0.3
• f >'*'£$' '
impossible to cut
impossible to cut
7
13
19pa
itoCOI
Fig.A-1.9 Cutting surface and cutting roughnessas parameters of laser power and cutting speed
OOoo
Total powerCW powerDutyPW powerDuty
DefocusAssist gas
Cutting conditions
M250W:650W:50%:600W:29%:-0.4 mm:Nitrogen
Cutting speed(m/min)0.1
0.15
0.2
0.3
0.35
Front surfaceCutting surfaceBack surface Cross section
impossible to cut
Roughness(um)10
16
37 I
2Oo
Fig.A-1.10 Cutting surface and surface roughnessas parameters of laser power and cutting speed (1)
OO
I
Total power :1500WCW power :900WDuty :50%PW power :600WDuty :29%
Defocus :-0.4 mmAssist gas :Nitrogen
Cutting conditions Cutting speed(m/min)0.2
0.25
0.3
0.35
0.4
Front surfaceCutting surfaceBack surface Cross section
impossible to cut
Roughness(urn)10
12
16
29
>
2OO
Fig.A-1.11 Cutting surface and surface roughnessas parameters of laser power and cutting speed (2)
00en
Cutting conditions
Total power M250WCW power :650WDuty :50%PW power :600WDuty :29%
Cutting speed :0.2 m/minDefocus :-0.4 mmAssist gas :NitrogenWelding joint :Butt
Cutting surfaceFront surface
msmmmmmm
Back surface Cross sectionRoughness
(um)13
SO
I
Fig.A-1.12 Cutting surface and surface roughness with horizontal position
Welding conditions Bead appearanceFront surface Back surface
Macroscopicobservation
D i stort i on(mm)
II—>00
Total powerCW powerDutyPW powerDuty
Welding speedDefocusShield gasWelding joint
1870W
:50%:760W:29%:0.25 m/min:-0.4 mm:Nitrogen:Butt
0.54
^^^^^m^^• I- .i !|
0.59
i n 1 ' ••!;•!,
Fig.A-1.13 Bead appearance and macroscopic observation by rewelding
JAERI-Tech 99-048
Optical fiber (10m)
4kW-YAG laser oscillator
6-axis robot
a)Schematic diagram of equipment
b)Processing equipment c)Laser head
Fig.A-2.1 High power YAG laser system
- 1 8 7 -
JAERI-Tech 99-048
Welding condition Defocus(mm)
Macroscopi cobservation
Laser powerWelding speedAssist gasGas flow rateWelding joint
:3.8 kW:0.3 m/min:Nitrogen:70 l/min:Butt
1
0
-1
-2
-3
Fig.A-2.2 Macroscopic observation as a parameter of defocus
- 1 8 8 -
Welding conditions Laser power(kW) 0.2
Welding speed (m/min)0.3 0.4 0.5
00CD
DefocusShield gasGas flow rateWelding joint
:-1 mm:Nitrogen:70 l/min:Butt
3.4
3.6
3.8
Ii
£oo
Fig.A-2.3 Macroscopic observation as a parameter of laser power and welding speed
Welding conditions Microscopic observation Deta iILaser power :3.6 kWWelding speed:0.3 m/minAssist gas :NitrogenGas flow rate".70 l/minWelding joint:Butt -•'•*-*
:l:-^^-J^tsc-u\
Fig.A-2.4 Microscopic observation under optimum welding conditions
Laser welding conditions 0.4 0.8Gap(mm)
1.2 1.4
ii—iCOi—>
i
CW laser powerWelding speedDefocusStand offAssist gasGas flow rateWelding joint
:3.6KW:0.3m/min:-1.0mm:5mm:Nitrogen:0.07m3/min:Butt
Inter layer metal thickness :0.8mmPlate thickness :7.6mmPlate material :SS316LN
Cross section
Bead appearance 55oCOtoi
o
CO
CO
Fig.A-2.5 Bead appearance and macroscopic observation as a parameter of gap
Laser welding conditionsFeeding rate
0.40.2m/min
Gap (mm)0.8
LOm/min1.2
0.6m/min
CO
I
CW laser powerWelding speedDefocusStand offAssist gasGas flow rateWelding jointWire diameterPlate thicknessPlate material
:3.6KW:0.3m/min:-1.0mm:5mm."Nitrogen:0.07m3/min:Butt:1.2mm:7.6mm:SS316LN
Cross section
Bead appearance i
oCO
CQ
Fig.A-2.6 Bead appearance and macroscopic observationas a parameter of gap and filler wire feeding speed
Laser welding conditions 0.4Gap(mm)
0.8 1.2 1.4
GO
I
CW laser powerWelding speedOefocusStand offAssist gasGas flow rateWelding jointInterlayer metalPlate thicknessPlate material
:3.6KW: 0.3m/m i n:-1.0mm:5mm:Nitrogen:0.07mVmin:Butt
thickness :0.8mm: 7.6mm
•-SS316LN
0.8
o\
Gap
Cross section
Bead appearance 33-
O
CO
Fig.A-2.7 Bead appearance and macroscopic observationusing interlayer metal as a parameter of gap
Welding conditions Bead appearanceFront surface Back surface
Macroscopicobservation
Laser powerWelding speedDefocusAssist gasGas flow rateWelding joint
:3.6 kW:0.3 m/mini-1 nm:Nitrogen:70 l/min:Butt
mmm
25oCOCO
i
Fig.A-2.8 Bead appearance and macroscopic observation with 2 mm mismatch welding
JAERI-Tech 99-048
500
400
• § 3 0 0
200
CC
100
1 v i
AS^IE Jacke&O'Dnnell curve]for stainless steel
Master curve for I-butt jointof stainless steel
I
I05 10s
Fatigue life (cycle)
10'
Fig.A-2.9 Results of fatigue strength test
- 1 9 5 -
Cutting conditions Cross section of cutting surfaceCW 3 . 6 k W CW 3. 2kW PW 6kW (peak power)
Cutting speed :0.4 m/minDefocus :0 mmAssist gas :NitrogenGas flow rate :175 l/min
' I ' ' ! I l l ; ' I '
a>o
Fig.A-2.10 Cross section of cutting surface as parameters oflaser oscillation type and laser power
II—»
Cutting conditions
Cutting speedDefocusAssist gasGas flow rate
:0.4 m/min:0 mm:Nitrogen:175 l/min
Macroscop i c observat i onCW 3.6kW CW 3.2kW PW 6kW (peak power)
>
Fig.A-2-11 Macroscopic observation as parameters oflaser oscillation type and laser power
JAERI-Tech 99-048
400
CS
ePi 300
2200j
ig loo
1/5
— f •
Kisi Top 0.5mm
1771 Middle 3.5mm
[XXI Bottom 6.5mm
Pulse CW,3.2kW, CW,3.6kW
Fig.A-2.12 Results of surface roughness as parameters oflaser oscillation type and laser power
s
I . 10
05 -
1.00 -
& 0.95
0.90
:
Pulse,0.4m/min CW^.2kW,0.6m/min
Fig.A-2.13 Results of kerf width as parameters oflaser oscillation type and laser power
4>
4 -
3 -
2 -
I -
--__
Pulse,0.4m/min CW^.2kW,0.6m/min CW^.6kW,0.6m/niin
Fig.A-2.14 Results of bevel angle as parameters oflaser oscillation type and laser power
- 1 9 8 -
JAERI-Tech 99-048
6
| 5
O 4
03
3 -
2 -
GOCO
2 o mmmmm ilillillPuke,0.4m/min CW,3.6kW,0.6m/min
Fig.A-2.15 Results dross quantity as parameters oflaser oscillation type and laser power
-I 5
03
3
HI
cS 0
ti
ll
1 1
1 1
.1
.1
.1
.1
.
1
•
1 1
11
1 1
1 1
1
.1
.1
.1
.
PuJse,0.4m/min CW,3.2kW,0.6m/nun CW,3.6kW,0.6m/min
Fig.A-2.16 Results of spatter quantity as parameters oflaser oscillation type and laser power
- 1 9 9 -
JAERI-Tech 99-048
Cutting conditions Cutting speedOn/in in)
Cross section
Laser powerDefocusAssist gasGas flow rate
:3.6 kW:0 mm:Nitrogen:175 l/min
0.3
0.4
0.5
0.6
0.7
0.8
i!ni!iiniiii!fTiiTnffifiminiiinifntiniii|[[
impossible to cut
Fig.A-2.17 Cutting surface as a parameter of cutting speed
- 2 0 0 -
CO
o
Cutting conditions
Laser power :3.6 kWCutting speed :0.7 m/minDefocus :0 mmAssist gas :Nitrogen
Assist gas flow rate(l/min)
125
150
175
Cross section
,,,„,„, ,, ^[.inhninniMiMiin;)^!
lilillllHilHlililHIIllll'lllHiipHIIliilinilHK
Vr|i!!iinii;i!l!|l!;iil!!i:;ii!!l!i;;!li|!lll|l!l!|l
I
Fig.A-2.18 Cutting surface as a parameter of assist gas flow rate
JAERI-Tech 99-048
Cutting conditions Cutting speed(m/min)
Macroscopicobservation
Laser powerDefocusAssist gasGas flow rate
:3.6 kW:0 mm:Nitrogen:175 l/min
0.3
0.4
0.5
0.6
0.7
0.8 impossible tocut
Fig.A-2.19 Macroscopic observation as a parameter of cutting speed
- 2 0 2 -
O
oo
Cutting conditions
Laser powerCutting speedDefocusAssist gas
:3.6 kW: 0. 7 m/m i n:0 mm:N i trogen
Assist gas flow(l/min)
rate
125
150
175
Macroscopicobservat i on
ii
soo
Fig.A-2.20 Macroscopic observation as a parameter of assist gas flow rate
JAERI-Tech 99-048
Eai.. 300 -
3D
o
CO
200 -
100 -
Fig
1
•L.
.1, -
x_"
r*"
.
F
1-"*"
«
— • - .
>
—
«
Top 0.5mm
Middle 3.5mm
Bottom 6.5mm
0 . 3 0 . 4 0 . 5 0 .6
Cutting speed (m/min)0.7 0. i
A-2.21 Results of surface roughnessas a parameter of cutting speed
400ssE> 300 -on
en
O
V
us
CO
200 -
t o o -
I20
3.6kW, 0
- ¥ ^
7m/min
•
I.
—•—Top 0.5mm—•--Middle 3.5mm—*~— Bottom 6.5mm
, -•
•
130 140 150 160 170 110Assisting gas flow rate (I/min)
Fig.A-2.22 Results of surface roughnessas a parameter of assist gas speed rate
I .10
£ I.05
1.00
° - 9 5
0.90
—-f-
3.6kW
3.2kWPulse
0.2 0.4 0.6 0.1
Cutting speed (m/min)
Fig.A-2.23 Results of kerf width as a parameter ofcutting speed
- 2 0 4 -
I .10
g 1 .05
i 1.00
•3 0.95
120
JAERI-Tech 99-048
3.6k\V,0.7m/min
140 160 ISO
Assisting gas flow rate (I/min)
Fig.A-2.24 Results of kerf width as a parameter ofassist gas flow rate
usu
4 -
3 -
2 -
1
\ \ \
A--'"'"
1
/
/
• '
—•—3.6kW
— • — j J k W
••A- Pulse
-
•
0.2 0.80 . 4 0 . 6
Cutting speed (m/min)
Fig.A-2.25 Results of bevel angle as a parameter ofcutting speed
5
s -
•S 3
£" 2
l6kW,0.7m/min
120 140 160 180
Assisting gas flow rate (1/min)
Fig.A-2.26 Results of bevel angle as a parameter ofassist gas flow rate
- 2 0 5 -
JAERI-Tech 99-048
0£SI
2 -
CO
gQ « • l
——3.6kW
— * - 3.2kW
0.2 0 . 4 0 . 6Cutting speed (m/min)
0.8
Fig.A-2.27 Results of dross quantity as a parameter ofcutting speed
= 5
4 -
3 -
2 -
a1
COCO
sp
i
3.6kW, 0.7m/min
;
i120 140 160
Assisting gas flow rate (1/min)180
Fig.A-2.28 Results of dross quantity as a parameter ofassist gas flow rate
5 ' -'©
CS
C8
CO 0 . 2
2 -
I -
ta„x-_.._.. ^ f c ^ _ _ - _ - _ _ -——3.6kW- - — 3.2kW
0 .4 0 . 6Cutting speed (m/min)
0.8
Fig.A-2.29 Results of spatter quantity as a parameter ofcutting speed
- 2 0 6 -
E
"5b 5
4 -
Is 3
2 -
120
JAERI-Tech 99-048
j , . •
$.6kW, 0.7m/min
140 160 180Assisting gas flow rate (1/min)
Fig.A-2.30 Results of spatter quantity as a parameter ofassist gas flow rate
- 2 0 7 -
CO
o00
I
Welding conditionsLaser power :3.6 kWWelding speed:0.3 m/minAssist gas :NitrogenGas flow rate:70 l/minWelding joint:Butt
M i croscoDi c observat i on
•* - *-c-*
r [I ,"
uSSk
Detaila
b
c
* "As- ^
I* •
'- ^
-Vi .1 S?
_ ;n:"<C;
w e — •- _ - --
Fig.A-2.31 Microscopic observation by rewelding
JAERI-Tech 99-048
Appendix-B
Leak Detection Methods and Tests
B- l Experimental Data on Leak Detection and Localization
1. Leak detection and leak localization results obtained in tokamak experience.
Refer to Fig.B-1.1 andFig.B-1.2
2. Leak detection and leak localization results using a 1st stage leak detection tool developed in thisR&D (a directional nozzle wan not extended into branch pipe.)
Refer to Fig.B-1.3 to Fig.B-1.13.
3. ConclusionsAs a results of tokamak experience and the 1st stage experiment, a nude type ionization gauge
with a directional nozzle can detect 10~8 Pa*m3/sec He, so that this method is applicable to the leakdetection of blanket cooling pipe. It is also expected that the localization ability will be less than 2 mmaccuracy.
- 2 0 9 -
II—•O
2) Baking -power supply and controlHe-standard leakSimulated defectVariable leak valveQuadrupole mass spectrometerHe-gas reservoirUnidirectional detector (Sensor)Vacuum vesselB-A GaugePirani gaugeTurbomolecular pumpRotary pumpManipulatorHe-leak detectorSensor control unitRecorderManipulator control -unitPotentiometer
>en
T
Fig.B-1.1. Leak detection systematic diagram of the facility
IT)
b el-X
5
3 •
= 700 mm/min
QI-7.0X10-10
Pa-m3/sec He
AJ-20•weo
QI.2.6x10''
Pa-m3/sec He
40
Vz = 350 mm/min
Qk7.0XlD"10 QI.2.6X10"7
PaTn3/soc Ho
.A/-5
SCANNING DIRECTION
Vi = |75 mm/min
QU7.0X10"10
Pa-m3/s6c He
• 7
• • 6
- • 5
QU2.6X10'7
Pa-m3/sec He
(Z)
Relation between scanning speed(Vz), distance(Al)and intensity of signal
QI=5.2X10"5 (PaTn3/sec He)
A 1=18 (mm)
Al=23
Al=33
Al=53
Al=93
-50 50
Pressure indicationon the sensor moved Z-direction
Fig.B-1.2. Leak detection and leak localization results
Reference: 9th symposium on engineering problems of fusion research (1981,Chicago)
>
8I
JAERI-Tech 99-048
2500
Orifice with Conductance of Blanket Module Pipes
Standard leak (10-7~10-9Pa-m3/sec)
Actuator (Linear Motion) View Port \ B-A gauge
SS Pipe (Poloidal Manifold)
Leak Test Equipment
• \ 11 /Center of Leak Point
Range of Leak Detection
Fig.B-1.3. Leak detection equipment of Blanket cooling pipe
- 2 1 2 -
ooI
Over view of Branch pipe partial model for leak test Over view of Probe head direction device
I
View of Vacuum pumping manifold side for Branch pipe partial model Over view of SL atached for branch pipe
Fig.B-1.4. Appearance of Leak detection test equipment
ICO
<t Directional nozzle(<*>D=3,L=8)
Probe Head
Vacuum
0 26
SSRod
>
CD
55oCO
Cable SS Pipe (Poloidal Manifold)
Fig.B-1.5. Probe head construction
Detection does helium flowing into vacuum exhausted pipe through dummy leakpoint (or inert gas), and scan along manifold inner wall with attached probe withdirectional nozzle, and leak localized.
Standard leak
Ito
Branch pipe50A i
Fig.B-1.6. Concept of Leak detection test
JAERI-Tech 99-048
Manifold
Vacuum pumping
oCO
•Leak point 2A.2B
Orifice with conductance- of Blanket module
I
Leak point 1A.1B
'Leak point 4A,4B
Branch pipe
, Leak point 3A,3B
rvvProbe originand detection stat point
80l\
point Detectio I . _. ,end point ! B Point P r ° b e . t
Detection end point
start point
Blanket cooling pipe model
Probe head
Measuring position
Origin«=>End point
Scanspeed
(mm/min)
500
1000
Dummy leak position and Standard leak rate(Pa-m3/s)
1A
10-7
O
O
1B
10-8
O
o
2A
10-7
Can't detect
-
1A+3A
10-7
O
O
Fig.B-1.7. Basic performance test results
- 2 1 6 -
JAERI-Tech 99-048
10'
CO
= 3coCOCD
10'
Dammy leak point:1 A, S.L open: after 1 min.S.L rate: 1.8x10"7Pa«m3/s, Scan speed: 0.5 m/min
•
-
Origin
Branch
0(mm)
Pipe A center
. , 1 . . . . . . . . . 1 , . , .
—
11
1......
Middle position 340
, , , , , 1 , , , , , , , , ,1 , , ,
Probe
- Pipe
w.. . . .
(mm)
10 20 30 40 50
Time (sec)
10-3
60 70
910
8 10
710
6 10
5 10
CCO
COCO
D.CD
-QO
10"
CCD
CD3COCOCD
10'
S.L open: after 5 min.
Probe
Pipe!
Origin 0 (mm) Branch Pipe A center Middle position 340 (mm)l
10
9 10
8 10 •*
710 *
6 10 "*
5 10 "
CC
CD
ores
suob
e i
4 1010 20 30 40 50 60 70
Time (sec)
10
CC
COCOCD
10'
-
-
Origin
Branch
0 (mm)
S.L
Pipe A center
open: after 10 min.
I —I
Middle position 340
. . .I i
Probe
-
— Pipe |
(mm)
.I
-
10 20 30 40 50
Time (sec)60 70
tA50iO-l>SC
10 J
- 910
- 8 10
- 710
6 10
5 10
4 10
CCO
Z3COCOCD
Q .
CD_ QO
D L
Fig.B-1.8. Results chart 1-1
- 2 1 7 -
JAERI-Tech 99-048
10
cC
ricocoCD
10"
Oammy leak point:1 A, S.L open: after 1 min.S.L rate: 1.8x10"7Pa«m3/s, Scan speed: 1 m/min
Probe
Pipe
Branch Pipe A center
Origin 0 (mm) Middle position 340 (mm)
I10 20 30
Time (sec)
10 '
910
810
7 10
6 10
40 501A7SI-1ASC
5 1 0
CO
COCOCD
Q .
CDX!O
10
CO
CD
coco
2a.
10
10"
S.L open: after 5 min.
Probe
I — Pipe!
Origin 0 (mm) Branch Pipe A center Middle position 340 (mm)
10
9 10 '4
8 10 "4
7 10- 4
6 10 "*
(Pa)
CD
—i
essi
Q.
'obe
10 20 30
Time (sec)
S.L open: after 10 min.
40 50510
CO
CD
COCOCD
10"
•
Origin
iBranch
0 (mm)
. . . I
Pipe A center
I
c
* 1 i a i
Middle position 340
. . ."V
i 11
(mm)
1 . . .
Probe
- Pipe|
10
9 10
- 810
- 710
- 610
- 5 10
CO
CDZSCOCO
CL
CD
oCL
10 20 30
Time (sec)
4 1040 50
1A7510-&ASC
Fig.B-1.9. Results chart 1-2
- 2 1 8 -
JAERI-Tech 99-048
CC
CD
:5cocoCD
10'
10 '
10 '
Dammy leak point: 1B, S.L open: after 1 min.S.L rate: 2.1x10"8Pa«m3/s, Scan speed: 0.5 m/min
Branch Pipe A center
Origin 0 (mm)
Probe
- - - Pipe
Middle position 340 (mm)
10 20 30 40 50
Time (sec)
6 0 7 01BS01-5.ASC
910
8 10
710
610
510
COO
CD
13COCOCD
CD. QO
10
cc
CD
COCOCD
10
S.L open: after 5 min
Branch Pipe A centerOrigin 0 (mm)
L^
" m i _
Probe
Pipe|
Middle position 340 (mm)
I . . . .I.
10 20 30 40 50
Time (sec)
60
10"
910
810
710
610
70510
CC
CD3COtoCD
CD
O
til
10"
CC
CD
rsCOCOCD
10 "5
-
Origin
• t • i 1 1 1 1
Branch
0 (mm)
L...
TPipe
ii .1
S.L
A center
II,.,,,
o p e n :
——" »
i
after 10 min
m ii-a-n Mi
Middle position
,. .1 1 . . .
— Pipe
-
-
> m>
340 (mm)
-
•
1
10 "J
- 910
- 8 10
- 710
- 610
• 5 1 0
10 20 30 40 50
Time (sec)60 70
1B501O-1ASC
410
Fig.B-1.10. Results chart 1-3
CO
CD
13COCOCD
Q .
CD
O
- 2 1 9 -
Pressure (Pa) Pressure (Pa) Pressure (Pa)
itotooI
• n(5"b
J3(D<
O
0)
ro
H
CD
o
eno
eno
: O3 .
'. "S.; o
;
-
L
I,
, ,3ro
3-o
o
g.CD
f fuOu>iti
; oL "
-
L
i
•a
KB
; fri
Pipe|
Probe
1 1 1 1 1
o•a
p
a>
o3.3'
-si
O
CO CO
o
d3CD
CD oO
: A 3
Q.CD
•a
o
1"
St .
o o-vj 5"
•o rrl 1«5§ §
"8 *a _J.P 3in 51
3 '35'
en
oL
o
00 03
O O
Probe pressure (Pa) Probe pressure (Pa) Probe pressure (Pa)
JAERI-Tech 99-048
10"
cc
:50303
10"
Dammy leak point:"! A&3A, S.L open: after 1 min.S.L rate: 1.8x10"^Pa«m /s, Scan speed: 0.5 m/min
_--
"~~tm__Lr
Branch F
Origin 0 (mi
ipe A center
TI)
r.. . i i
.. , _,__ _
11
Branch Pipe B center
Middle position 340.
. . . i i , . . . ! . . . . i . .
Probe
Pipe| -
mm)
10'
- 9 1 0
CC
20 40 60 80
Time (sec)100 120
AA501-5-ASC
03
810 °-CD
O
Ql
7 1 0 " 4
10"
en
inenCD
Ql
10"
Branch
~tlOrigin 0
Pipe A center
Jf lrA-uLtJu
(mm). . i . . . . . . . .
s
III / l l
. I . ,
.L open:
vammlhm 1
1 -
after 5 min.
Branch Pipe B
•MB illMiddle position
i . . . .
^ - -— • —..
center
I340 (mm)
. . . . ! . .
Probe
Pipe|
10
- 9 1 0
- 8 10
20 40 60 80
Time (sec)
CD
3
03Q
100 120
7 1 0 " Q
JQ
26 10 "4
10"
CC
03
O3
<D
10"
S.L open: after 10 min.
Branch Pipe A center
• t - -™.Origin 0 (mm)
Probe
Branch Pipe B center
Middle position 680 (mm)
i i i . . . . ! . • . • 1 1 • • . • . . i
10"
9 1 0 CO
8 10 CD1303
7 1 n -4 03/ 1U Q
. CD610 -g
20 40 60 80
Time (sec)100 120
AAS01O-SASC
5 10
Fig.B-1.12. Results chart 3-1
- 2 2 1 -
Pressure (Pa) Pressure (Pa) Pressure (Pa)
roto
Tlcp'ma
W•
3D<D(
U)
oD)3.COro
oTJCD• •
toa?ro
3CD
,»»—»(/)CDO
o
CO
o
o r
o r
o
i I L
--j
'•_
:;—:
in 0 (mm
)
—9
J\
1
mR
•oosil
CD•anch Pip
•j, ro
r >
J30
ro
II1
CD
snchP
ip
,5- ^ «3 CD
- utCD
; o: 1": _§_
*•
m
\
S o
rs
I
!
ir
t'r
•]
I
ii
—ij
•
TJ
ro
1 1
T l
3crro
t
1
!
OTJ(0
CD
cn35"
cno o
i.
2T
i
OO
Probe pressure (Pa) Probe pressure (Pa)
- J. i- i
Probe pressure (Pa)
^ (SI) t
311 * 5
H
V.
±•?-
ft
w
•
ft
ffi ft1* ft
*
T
V"
-e
7
X
• 9
ny
y
y
X 7
ft
7
t*
x"
T
•y'7
A
T
y
7
y
y
m
kgs
AK
mol
cd
rad
sr
* 3 >SHIft¥ft
mffl * a
ft /; , l£> /j
£ * , ft W £"&. X\ S • ^i 1"J
aft, MIT:, iiMf]s& ^ ^ Mif IO A M
S x\ ffi K3 y y 9 9 "y x
B * S; ft•1 y 9' 9 9 y T-
-b >u •> ^ x £ FS
it £ffi ft
ft W Bt»J£ W IS •
m m *j «
•y
7
7
y
7
X
- X
t i
;u
9'y
« ft
^ - \-X *
3 -
y
— D
;u
7 7
-
- > yj r .
X
y ')
'7
y
; l /
IV
h
y
h
KA
X
7
-
u y v x ft- y
9
9 \s
- " • = • " "
y
X
'f
HzNPaJWCVF
ns
WbTH°Clm
lx
BqGy
Sv
(16© SI ¥(4
s- 'm-kg/s2
N/m2
N-mJ/sA-sW/AC/VV/AA/VV-sWb/m2
Wb/A
cd-srlm/m2
s"1
J/kgJ/kg
'J
Ig
g
• y
f .+:t i
ft
•
i *
a
y
1-
ft
min,
1.
t
eV
u
L
=L
h. d
leV=1.60218xl0- 'J1 u= 1.66054X 10"" kg
/-'*'
+
7
U
y ?' x-
-
y h
ft- o —
IJ
f
A
y
;u
-y
KA
IS EJ
A
b
bar
Gal
Ci
Rrad
rem
1 A=0.1 nm-10-10m
1 b=100fm2 = 10-!'m2
1 bar^O.l MPa = 10sPa
1 Gal=l cm/s2 = 10-2rn/s2
1 Ci=3.7xlO'°Bq
1 R = 2.58xlO-'C/kg
1 rad = lcGy = 10 2Gy
1 rem=lcSv=10" !Sv
10"
10"
10'2
10'
10'
10!
102
10'
io- '
io-2
10"3
io - '
10-io- ' 2
i o - "I O - "
H
+
-f
T
-fe
7"
t°
7
T
7
•
7J
• y
y x')
-f f D/
Z?
i A 1-
EPTGMk
h
da
d
c
m
un
Pf
a
(It)
i - 5 i ±
19
ufflfflli
eV
.. 7 y b, T-'i*,
3. barli.
Cf
r, bamfci
N(=10*dyn)
ft
1
9.80665
4.44822
kgf
0.101972
1
0.453592
Ibf
0.224809
2.20462
1
1 Pa-s(N-s/m2)=10P(.t:rx')(g/(cm-s))
lm2 /s=10'St(x h - ? x ) ( c m 7 s )
It MPa(=10bar)
1
0.0980665
0.101325
1.33322 x 10-'
6.89476 x 1Q-3
kgf/cm2
10.1972
1
1.03323
1.35951 x 10-
7.03070 x 10-
atm
9.86923
0.967841
1
1.31579 x 10 3
6.80460 x 10-2
mmHg(Torr)
7.50062 x 103
735.559
760
1
51.7149
lbf/in!(psi)
145.038
14.2233
14.6959
1.93368 x 10-
1
X
1
ft:
J( = 10'erg)
1
9.80665
3.6x10'
4.18605
1055.06
1.35582
1.60218 x 10-"
kgf 'm
0.101972
1
3.67098 x 10 s
0.426858
107.586
0.138255
1.63377 x 10''"
kW- h
2.77778 x 10-'
2.72407 x 10-'
1
1.16279 x 1 0 '
2.93072x10 •'
3.76616 x 10"'
4.45050 x 1Q-"
cal«t»£)
0.238889
2.34270
8.59999 x 10s
1
252.042
0.323890
3.82743 x 10-20
Btu
9.47813 x 10-'
9.29487 x 10-3
3412.13
3.96759 x 10"3
1
1.28506 x 10"3
1.51857x10-"
ft • Ibf
0.737562
7.23301
2.65522 x 10'
3.08747
778.172
1
1.18171 x 10-"
eV
6.24150 x 10'8
6.12082x 10"
2.24694 x 10"
2.61272x 10"
6.58515 x 102 '
8.46233 x 1 0 "
1
Bq
3.7 x 10"
Ci
2.70270 x 10"
1
Gy
1
0.01
rad
100
1
C/kg
2.58 x 10-
R
3876
1
1 cal = 4.18605 J(ttitffi)
= 4.184J U&it'f-)
= 4.1855 J (15 X )
= 4.1868 JC
1 PS
= 75 kgf-m/s
= 735.499 W
Sv
1
0.01
100
1
12 f\ 26
