abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals...
TRANSCRIPT
![Page 1: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/1.jpg)
Abrasive and impact-abrasive
wear testing of steels for
mining, transporting, and
mineral processing
Hard rock tribology seminar
4.11.2014
Vilma Ratia Tampere University of Technology,
Tampere Wear Center,
Tampere, Finland
![Page 2: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/2.jpg)
Contents
• Wear – what is it?
What are wear resistant steels?
• How can wear resistance be controllably
measured?
• How wear is shown in steels?
• Which factors affect wear of steels?
![Page 3: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/3.jpg)
The durability of machinery in raw
materials extraction and processing is
increasing in importance
geosyntheticsmagazine.com
ruukki.com
ruukki.com
![Page 4: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/4.jpg)
0.1
42
0.1
58
0.1
63
0.1
65
0.1
72
0.1
73
0.1
76
0.1
80
0.1
86
0.1
89
0.1
92
0.1
99
0.2
02
0.2
08
0.2
16
0
100
200
300
400
500
600
700
800
900
1000
0.000
0.050
0.100
0.150
0.200
0.250
0 2 15 4 14 3 10 11 5 24 18 17 6 16 1
Su
rface
hard
nes
s [H
V5]
Mass
loss
[g]
Wear resistant steels have higher
strength and hardness than
conventional structural steels
• Commonly graded
according to hardness
in Brinell scale:
400HB, 500HB, 600HB
• Tensile strength
typically 1200-1600
MPa
• Notch impact energy at
-40C typically 30 J/cm2
• Microstructure often
martensitic, but bainite,
ferrite, pearlite and
austenite are also
possible
ruukki.com
N. Ojala et al. WTC 2013 & Wear 317(2014)225-232
![Page 5: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/5.jpg)
Wear resistant steels can be used in a
wide range of applications
Examples of
applications:
• Agriculture
(harvesters, ploughs)
• Earth moving
(tippers, excavator
buckets)
• Forestry
(frost and rock
rippers, stump
processors)
• Mining
(wheel loader
buckets, stock pile
conveyors, sieves,
conveyor belt
hoppers)
johndeeredistributor.fi
deere.fi ruukki.com
sandviktamrock.fi
![Page 6: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/6.jpg)
• Impeller (samples) 700 rpm
• Tumbler 30 rpm
• 900 g of granite(10-12,5 mm)/15 min • Altogether about 3-22 kg
• Sample size 75 x 25 x 10 mm
• Sample angle 30°, 60° or 90°
• Test duration 45-360 min
Impeller-tumbler simulates wear in
hammer mills, silos, loading of tippers
• Impeller-tumbler combines
impacts and abrasive wear
Wear testing enables the evaluating
of materials’ wear performance in
controlled conditions
metso.com ruukki.com
![Page 7: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/7.jpg)
![Page 8: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/8.jpg)
Uniaxial crusher simulates wear in
crushers and tippers while transport
• Crushing of gravel with high force up to 86 kN
• Fresh granite (4-6,3 mm) for each crush
• Typical test duration 1000 compressions
Sample
Abrasive cup
Supply tube
ruukki.com
![Page 9: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/9.jpg)
Crushing pin-on-disc simulates wear
in crushers and unloading of tippers
•Abrasives as loose particles
• 500 g in a test
•Used force 200 N
•Pin diameter 36 mm
•Disc diameter 160 mm
•Test duration 30 minutes (240 crushes)
• Running-in of 20 minutes
ruukki.com
![Page 10: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/10.jpg)
1
0
![Page 11: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/11.jpg)
Steels and abrasives have many kind of
interactions
• Deformation:
– Ploughing
– Wedge formation
• Embedding of abrasives
• Indentations
• Fatigue due to
subsequent impacts
• Chip formation
• Cutting
![Page 12: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/12.jpg)
The harder steels have clearer scratches
and less abrasive remnants
S355 500HB
S355 500HB
![Page 13: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/13.jpg)
Hardening can enhance wear resistance
• Work hardening takes place in
impacts, but also in high-stress
abrasion
• The tendency of work hardening is
beneficial, unless it makes the top
layer brittle
400HB 650HB V.Ratia et al. Wear 301(2013)94-101
![Page 14: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/14.jpg)
Depending on the contact, hardness may
have a different role
V. Ratia et al. Tribology Online 8(2013)152-161
![Page 15: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/15.jpg)
Abrasive properties affect the wear
mechanism
• Abrasiveness, crushability, toughness, hardness etc.
• Size, size distribution and shape
Abraded with quartzite: Hardness 1200 HV,
crushability 74%, abrasiveness 1840g/t
Abraded with tonalite: Hardness 960 HV,
crushability 18%, abrasiveness 1460g/t
![Page 16: Abrasive and impact-abrasive wear testing of steels for mining, transporting, and minerals processing](https://reader033.vdocuments.us/reader033/viewer/2022052217/55a209951a28ab8b368b4586/html5/thumbnails/16.jpg)
WANTED:
Wear resistant steels
• High hardness and strenght
• Good impact toughness and ductility
• Work hardening
• Adequate machinability, weldability etc.
• Decent producing costs
400HB 650HB 500HB