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voestalpine Böhler Welding1 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019www.voestalpine.com/welding
voestalpine Böhler Welding
Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals
TRUSTED IN EXTREME CONDITIONSPUSHING STEEL SOLUTIONS
TO NEW LIMITS VOESTALPINE OIL AND GAS
ABERDEEN, JUNE 2019
Bernd HobergGlobal Application Engineeringvoestalpine Böhler Welding GroupHamm, Germany
voestalpine Böhler Welding2 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
vaBW Germany / Hamm
Annual capacity: 48,000 tons solid wire, flux
voestalpine Böhler Welding3 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Content:
Characteristics of DSS and SDSS
Welding Procedures vs. Tendency to Pore Formation
Corrosion Testing
Conclusion
Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals
voestalpine Böhler Welding4 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
DSS 2205 type – UNS 32205
SDSS 2507 type – UNS 32760
incr
easi
ng c
orro
sivi
ty o
f wat
ers
904L - X2CrNiMoCu20-25
317L - X2CrNiMo18-15-4
316L - X2CrNiMo17-12-2
304L - X2CrNi19-11
6%Mo Super Austenitic Stainless Steels 926L - X1NiCrMoCuN25-20-7
Titan: grade 2, grade 12
Nickel Alloys: Alloy 625, C-Alloys, e.g. 59,C-276, C 22 etc.
„ Stainless Steels:Austenitic Stainless Steels
Material Selection – e.g. for Seawater Environments
resistance against seawater at ambient temperature
voestalpine Böhler Welding5 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
ASTM A 923-8
corr. test temp.* BM + WM:22°C/24 hCVN -40°C BM, HAZ: 54J, WM 34 J*) detection of intermetallic’s e.g.
sigma phase
NACE MR 0175-2003 PREN Cr%+3,3(Mo+0,5W)+16N%
30 ≤ PREN ≤ 40: ferrite 35-65%H2S: 10kPA
Max. working temp 232°C Cast and wrought products
ASTM G 48 A – 2003
Methode A: 6 mass-% FeCl3CPT: 25°C/24 h WM + BM
NORSOK MDS 42(rev.5)UNS S31803, UNS S 32205Ferrite 35 - 65% WMRp0,2 > 450, Rm > 620MPa,A > 25%CVN -46°C > 45J
CPT G 48 A: 25°C/24h WM< 4g/m2 WM
NORSOK M-601(2016)Ferrite 30 to 70% WMCVN -46°C: 27 J WM+FLHardness max 36 HRC(DIN EN ISO15156-3)
22Cr - DSS Interactive Requirements
voestalpine Böhler Welding6 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
NACE MR 0175-2003PREN Cr%+3,3(Mo+0,5W)+16N%
40 < PREN ≤ 45; ferrite 35-65%H2S: 20 kPA
Max. working temp 232°C Cast and wrought products
NORSOK MDS 52 (rev.4)PREN Cr%+3,3Mo+16N% ≥ 40Ferrite 35-65% WMRp0,2 >550, Rm >795MPa, A > 25%CVN -46°C > 45JCPT: ASTM G48 A: 50°C/24h
no pits, < 4,0 g/m2 => WM/BM
ASTM G 48 A + E – 2003A: 6 mass-% FeCl3E: 6 mass-% FeCl3 +1%HClCPT: BM and WM
Start temp 20°C / 24h ∆T: 5°C / 24 h
NORSOK M-601(2016)Ferrite 30 to 70% WMCVN -46°C: 27 J WM + FLCPT ASTM G 48 A: 35°C/24h WM
no pits, < 4,0g/m2 WMHardness max 36 HRC (DIN EN ISO15156-3)
25Cr - SDSS Interactive Requirements
ASTM A 923-8corr. test temp.* BM: 40°C/24 hCVN -40°C BM, WM: negotiable! *) detection of intermetallicse.g. sigma phase
voestalpine Böhler Welding7 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Content:
Characteristics of DSS and SDSS
Welding Procedures vs. Tendency to Pore Formation
Corrosion Testing
Conclusion
Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals
voestalpine Böhler Welding8 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
GMA Welding / (MIG/MAG)Process: from manually
assisted to fully automaticShielding gases: inert/active; Ar, He and/or
CO2 and their mixturesAdvantages: high deposition rates and welding
speed, low heat input possibleDisadvantages: positioning of the torch, spatters
and weld defects e.g. lack of fusionand porosity SDSS PREN > 41)
Welding Consumables: Thermanit 22/09, Thermanit 25/09 CuTCN 22/9-IG CN 25/9 CuT-IG
voestalpine Böhler Welding9 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Spray arcFine droplets without short circuitShielding gas: Ar and mixed gases e.g. Ar/He/CO2 - bal/30/0,5 Welding position: PA, PB Typical parameters: I = 270 A, U = 29 V 1.2 mm ø,
Vwire 8 m/min
Pulsed arcDroplet segregation through "pinch effect"Pulse time, voltage, current and pulse background must be adjustedShielding gas: Ar and mixed gases s.o.Base metals: CRA, nickel alloys, aluminum Welding position: PA, PB, (PF)
wireelectrode
magnetic field
reduction
of area
Influence of the Shielding Gas on Droplet Transfer and Arc Mode
voestalpine Böhler Welding10 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
• unalloyed structural steel(minor requirement)
• CRA, Super Duplex
• Nickel alloys
• low-mediumalloy steels
• CRA, Duplex
• Aluminium
Shielding Gases for GMA Welding acc. DIN EN ISO 14175Symbol
reducing inert reactiveCO2 O2 Ar He H2 N2
1 1002 1003 Bal. 0,5 ≤ 95 1 0,5 ≤ 5 Bal. a 0,5 ≤ 5 2 0,5 ≤ 5 Bal. a
3 0,5 ≤ 3 Bal. a
0 5 ≤ 15 Bal. a
1 15 ≤ 25 Bal. a
2 3 ≤ 10 Bal. a
3 0,5 ≤ 5 3 ≤ 10 Bal. a
1 25 ≤ 50 Bal. a
2 10 ≤ 15 Bal. a
3 25 ≤ 50 2 ≤10 Bal. a 1 1002 Rest 0,5 ≤ 30 1 Bal. a 0,5 ≤15 2 Bal. a 15 ≤ 50 1 1002 Bal. a 0,5 ≤ 53 Bal. a 5 ≤ 50
0 1 100
Z
M1
Shielding gas components in volume %oxidizing inertmain
groupsub
group
I
N
M2
M3
C R
Further subgroups are listed in DIN EN ISO 14175
Gas mixtures with components, which are not mentioned in this table or gas mixtures with compositions out of the specified range.
a) For this classification argon can be partially substituted by helium
voestalpine Böhler Welding11 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Fluidity and arc stability lower than standard austenitic fillers (spatter)
Best results with synergic puls GMAW
Recommended shielding gas for SDSS:
Ar + 20-30% He + max. 0,5 % CO2
High BM nitrogen content influences sensitivity to porosity:
too thin or too thick beads increase risk
wrong joint preparation increases risk – high degree of fusion & trapping of nitrogen gas in solidifying metal
weld in a gap, root opening
Pulsed arc
Normal spray arc
Spatter in short arcSpatter in short arc
SDSS vs. 300 Series Stainless Steel - GMAW
voestalpine Böhler Welding12 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Heat# 98162
Heat# 100073
Overlay welding: 2 layers, 4 runs
Pore Formation in GMAW of SDSS Weld Metal – Review 2010s
voestalpine Böhler Welding13 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Super Duplex GMAW – Today
Pulse GMAW butt weld : Thermanit 25/09 CuT – Shielding gas:, Cronigon He 30 C (Ar/He/CO2 – bal / 30 / 0,25)
BM: UNS 32760 t = 15 mm, single - V groove 60 ° with backing run
X-ray acc. DIN EN ISO 10675-1 => acceptable 1
Heat# 104062
voestalpine Böhler Welding14 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
266279272287272277 262276 253 265
287 x 271 269293 273 261291 283 279296 280 271292 296 294276 281 x 285274 297 292 x284 292 279298 292 296
1 mm 308 1 mm 280 1 mm 289281 293 289272 304 303 x264 295 307277 302 296278 292 295285 296 x 275277 278 273282 275 273295 272 274277 270 253
285 x 269 269279 262 266280 264276284286274265
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Seite 1 von 1voestalpine Böhler Welding Germany GmbH
Härteprüfung nach 6507-1
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Super Duplex GMAW – Today
voestalpine Böhler Welding15 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
YS[MPa]
Z[%]
TS[MPa]
A5[%] LoF
-- 835 -- BM
Sample
Flat tensile specimen # 1-- 834 -- BMFlat tensile specimen # 2
Tensile Test
149
CVN-2[J]
CVN-3[J]
CVNave[J]
Toughness CVN
PHWT
u
CVN
VWT 0/2
Test temp.[°C]
- 40 158 150143
CVN-1[J]
147uVWT 0/2 - 46 136 145153
25%Cr Duplex Butt weld – S 32760 t = 15 mm in PA Thermanit 25/09 CuT / Cronigon He 30 C
----
voestalpine Böhler Welding16 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
YS[MPa]
Z[%]
TS[MPa]
A5[%] LoF
739 885 58 WM
Sampole
Round tensile test RT559 559 62 WMRound tensile 220°C
Tensile Test
124
CVN-2[J]
CVN-3[J]
CVNave[J]
Toughness CVN
PHWT
u
CVN
VWT 0/2
Test temp.[°C]
- 46 123 124125
CVN-1[J]
133uVWT 0/2 - 60 136 130122
25,127,6
Mechanical Properties – All weld metal Thermanit 25/09 CuT / Cronigon He 30 C
Heat# 104062
voestalpine Böhler Welding17 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
DSS: Thermanit 22/09 + Marathon 431CN 22/9 IG + Flux 805*
SDSS: Thermanit 25/09 CuT + Marathon 431CN 25/9 CuT-IG + Flux 805*
*)PWHT solution annealing
Wire Flux Combination SA Welding
voestalpine Böhler Welding18 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Features:
one wire electrode
one power source
one control
Advantages:
high deposition rate
Typical welding parameters: wire electrode diameter: preferred 2,0 mm - max. 2,4mmcurrent / voltage 240 - 350 A / 28 – 30 Vwelding speed: 45 - 50 cm/mininterpass temp: 100°Cheat Input: max. 12 kJ/cm flux: Marathon 431 (basicity 2,3 )
~ 25 mm
SA – Welding with SDSS Wire Electrode Thermanit 25/09 CuT
voestalpine Böhler Welding19 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Chg.: 100419
Pore Formation in SA Welded SDSS All Weld Metal Sample
Chg.: 98376All weld metal test specimen acc. EN ISO 1597-1
voestalpine Böhler Welding20 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Dimension Heat- no.
Sample-no.
C Si Mn P S Cr Mo Ni Al Cu N
UNS 32760 / 1.4501 6000x2000x15 L 74451 150316 0,025 0,27 0,51 0,021 0,002 25,2 3,62 6,94 - 0,54 0,22
Wire dia Flux
Thernanit 25/09CuT
- 100419 108JK 0,012 0,44 0,833 0,025 0,002 25,5 3,79 9,41 0,020 0,57 0,246
Thernanit 25/09CuT
Marathon 431
500x400x15 100419 / 1404784
XDM1 0,013 0,55 0,64 0,027 0,004 25,14 3,83 9,13 0,029 0,59 0,216
wire electrode
all weld metal
Base Materials
Chemical Composition
Weld metal
Test Specimen Remark
solution annealed 1120°C / 22 min / water
a) Chemical composition of base material and weld metal
Typical Properties SA Welded Sample
voestalpine Böhler Welding21 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Typical Properties SA Welded Sampleb) Mechanical properties of base material and weld metal
c) Optical microscopy WM FL BM
Dimension Heat-no. Sample no.
ReH / Rp1,0 Rm A5 CVN
-20CVN -20
CVN -20
CVN -40
CVN -40
CVN -40
CVN -50
CVN -50
CVN -50
SBB 4,0
RBB 4,0
FBB 4,0
6000x2000x15 L 74451 150316 615 815 25 198 196 186
Wire Electrode dia. Flux
Thermanit 25/09 CuT 2,0 mm
Marathon 431
500x400 x15
100419 / 1404784 2K71 811
GW 132 58 70 80 52 76 77 64 67 180° OK
180° OK
180° OK all weld metal
Charpy Impact Test [J]
solution annealed 1120°C / 22 min / waterUNS 32760 / 1.4501
RemarkTensile Test Bend Test d/a
Test Specimen
voestalpine Böhler Welding22 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Characteristics of DSS and SDSS
Welding Procedures vs. Tendency to Pore Formation
Corrosion Testing
Conclusion
Content:
Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals
voestalpine Böhler Welding23 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
ASTM G 48 A - CRA test specimens will be examined in 6% FeCl3testing solution at constant temperature and testing time for example 24 h.
Pitting Corrosion
Crevice Corrosion
DSS
SDSS
Critical Crevice Temperature (CCT) - Critical Pitting Temperature (CPT)
voestalpine Böhler Welding24 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Precipitation Behavior of (S)DSS
DSS SDSSCr 22,7 25,3Mo 3,3 3,7N 0,16 0,24
PRE >35 >41 YS (MPa) 630 732TS [MPA] 820 887Elong. [%] 30 26CVN [J],-40°C >100 >100
1000
300
M7C3 - CarbideCrN - Nitrid
σ - PhaseCr2N - Nitrideχ - Phaseγ 2 - Phase
M23C6 - Carbide
π - Phaseε - Phaseα - Phase
G - Phase
Time [h]
Tem
pera
ture
[°C
]
Mo, W, Si
CrMoWSi
Cr, MoCu,W
Cr, Mo, Cu, W
Properties of GTA weld metal:
DSS: Thermanit 22/09SDSS: Thermanit 25/09 CuT
voestalpine Böhler Welding25 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Corrosion Testing acc. to ASTM G 48 ESample Preparation Machined test specimen, Final layer: as weld brushed cut edges ground with grid 80 wetASTM G 48, Method C and E 6 mass - % FeCl3 +1%HCl
Test 24 h (attn. method C ⇒ 72 h!) Start temp 20°C ∆T: 5°C/24 hDetection: Critical Pitting Corrosion (CPT)Calculation: Corrosion rates e.g. mm/year or g/m2
voestalpine Böhler Welding26 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
ASTM G 48 E - Results of various Thermanit 25/09 CuT Weld Deposits
voestalpine Böhler Welding27 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Characteristics of DSS and SDSS
Welding Procedures vs. Tendency to Pore Formation
Corrosion Testing
Conclusion
Content:
Corrosion Resistance and Weldability a Challenge for Duplex Filler Metals
voestalpine Böhler Welding28 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
High thermal loading on the root pass increases the risk for:
precipitation of intermetallic phases !
reduced corrosion resistance
Cold-Pass HI: 8 - 12 kJ/cmBulky Root HI: 10 – 15 kJ/cm
HEAT INPUT =I x U x 60
VS x 1000 [KJ/cm]
Cold - Pass - Technique for SDSS
voestalpine Böhler Welding29 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Slow cooling rate in the case of HI > 15 kJ/cm
Increased risk of precipitation of intermetallics (sigma, chi)
Structural instability
Decreased corrosion resistance
Decreased toughness
Avoid high heat input in hot pass to minimize sigma in root bead
Interpass temp. < 120°C for DSS< 100°C for SDSS
Influence of Heat Input
ColdPass
Bulky Root
HEAT INPUT =I x U x 60
VS x 1000 [KJ/cm]
voestalpine Böhler Welding30 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Procedures and consumables: GTAW: wire rod PREN ≥ 41 (Norsok Calc.) for CPT requirements 35 - 40°C!
SAW: see above but don’t accept CPT > 35°C for joint welding (heat input !!!)
GMAW: wire electrode PREN ≥ 41 and appropriate shielding gas, FCAW is an alternative => Avesta FCW 2507/P100-PW NOR!
SMAW: PREN > 40 (Norsok Calc.) to achieve proper corrosion resistance
Welding practice and workmanship:Root and 1. and 2. layer: GTAWShielding gas: Ar + 2 %N2 (FM with PREN > 42 pure Ar to avoid porosity)
Purging gas: Ar + 2 %N2 or 95 N2 + 5 H2
Interpass temperature: max. 100°C
Heat input: root: 8 - 15 kJ/cm
layer 1. + 2. 5 - 12 kJ/cm
all others: 5 - 12 kJ/cm
Tack welding: welding on the root side not permitted
Welding of Super Duplex Steel
right handling ensuresa safe environment
voestalpine Böhler Welding31 | vaBWG B. Hoberg I SDSS Welding I 04.06.2019
Thank you!Bernd HobergT. +49/2381 [email protected]