Application oriented wear testing of wear resistant steels in mining industry
WEAR OF LASER SURFACE HARDENED STEELS
Transcript of WEAR OF LASER SURFACE HARDENED STEELS
WEAR OF LASER SURFACE HARDENED STEELS
4 Apr. 2013 Ing. Pavla Fišerová
RESULTS PUBLISHED IN THE PRESENTATION WERE OBTAINED IN THE SGS-2013-083 PROJECT
Laser Line (Pmax=4 kW), Kuka 16 HA [1]
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Overview
1) Laser surface hardening
2) Goal of the presentation
3) Overlap zone
4) Wear tests and materials
5) Pin-on-Disk test
6) Cyclic impact test
7) Conclusion
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Goal of the presentation
??? ???
Laser surface hardening [2]
Customers of MATEX PM would like to know whether the wear rate of laser-hardened steel is the same as or higher than that of induction-
hardened steel
Minimized distortion High quality of hardened layer High process speed Processing of complex shapes No surface cracks Environment-friendliness
Distinct transitional area Relatively low depth of hardened layer
LASER SURFACE HARDENING
- Different type and rate of wear - May lead to a high wear difference between overlap and laser track areas
Could we affect an overlap area?
Mould for automotive industry [3]
Cogwheel
gear pinion [4]
3) Sometimes we cannot control the overlap
2) In most cases, overlap is not used in functional areas
1) Overlap zones are not always necessary
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Overlap Zone
Why Study the Overlap Area?
Differences in wear rates !!!
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Specimen 2 hardening tracks
380 HV 10
653 HV 10
OVERLAP AREA
Fracture, C45 steel,magn. 10x
Fracture, C45 steel,
magn. 500x
C45 steel, magnification 50 x
C45 steel, magn. 500 x
Overlap zone
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Wear Tests
1) PIN-ON-DISK TEST
Aim of the test 1) Compare the wear behaviour of the laser track area and the overlap zone2) Compare the wear of laser-hardened
and induction-hardened materials
Test conditions
- wear profile was measured in Palacký university in Olomouc
Pin-on-Disk test [5]
Sample hardened by laser 6/13
- 42CrMo4 steel (ČSN 15 142)- Hardness after laser surface hardening: 55 HRC- Number of cycles: 100 000- PIN material: Al2O3
Pin-on-Disk Test Results
distance [µm]
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32102 33540
4487950580 50939
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72308 74814
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µm
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Laser hardened - overlap zone
Laser hardened – laser track
Induction hardened
Track 1 (Ø 30 mm)Track 1 (Ø 30 mm) Track 2 (Ø 35 mm) Track 3 (Ø 40 mm)
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ONLY 3 %
Wear tests
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Aim of test
Test conditions
- Number of cycles = 100 000- F = 400 N
- Materials
Impact test
Hammer
2) CYCLIC IMPACT TEST
1) Compare the wear of laser-hardened surface and induction-hardened surface
- 1.2379 (ČSN 41 9573)1) soft-annealed2) quenched and tempered
- 1.6582 (ČSN 41 6343)1) quenched and tempered
- 6 impact craters were created in each specimen- Crater area was measured → An arithmetic characteristic of the wear area was obtained- 1.6582 and 1.2379 steels were used
Sample
Impact test results
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1.2379 1.2379 QT 1.6582 QT
Laser hardened
Induction hardened
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Conclusion
- Average amounts of wear were evaluated for the overlap area and the laser track area- 42CrMo4 material
1) DIFFERENCES BETWEEN WEAR OF OVERLAP ZONE AND HARDENED AREA AFTER LASER SURFACE HARDENING (PIN-ON-DISK TEST)
Wear tests have not shown a large deviation in the amount of wear in the overlap area.
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1 2 3 4 5 6 7 8 90
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Track 1 (Ø 30 mm)
Track 1 (Ø 40 mm)
Track 1 (Ø 35 mm)
Laser hardened - hardened area
Laser hardened - overlapped zone
The biggest difference between amounts of wear in overlap and track zones was 3 % .
Conclusion
2) DIFFERENCES BETWEEN WEAR OF LASER SURFACE HARDENING (OVERLAP AND HARDENED AREA) AND INDUCTION HARDENING (PIN-ON-DISK TEST)
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1 2 30
5000100001500020000250003000035000400004500050000
32102 33540
44879
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µm
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Track 1 (Ø 30 mm)
IND
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LASE
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LASE
R H
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Wear tests revealed that the wear rate is much higher in induction-hardened steel than in laser-hardened steel
Reduced component life
Need for more frequent replacement in service
Approx. 15% increase in costs
Conclusion
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0
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110498
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a[µ
m2
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IND
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LASE
R
1.2379 QT
LASER
If you would like to have a lower wear...
3) DIFFERENCES BETWEEN WEAR OF LASER-HARDENED SURFACE (OVERLAP AND LASER TRACK AREAS) AND INDUCTION-HARDENED SURFACE (IMPACT TEST)
The cyclic impact test revealed considerably higher wear rates under dynamic loading in induction-hardened steel than in laser-hardened steel
[1] www.matexpm.com[2] www.sciencedirect.com[3] www.indiamart.com[4] www.mtjjg.com[5] www.laserarc.com
LITERATURE