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Effects of austempering and martempering processes on amount of retained austenite in Cr-Mo steels (FMU-226) used in mill liner

  • M. H. Shaeri
  • H. Saghafian
  • S. G. Shabestari
Article

Abstract

The presence of retained austenite gives rise to deterioration of the wear resistance and fracture strength of Cr-Mo steels in many cases. Thus, the effects of heat treatments including direct quenching, martempering, and austempering on the retained austenite existing in the microstructure of these steels were investigated. Specimens were austenized at 950 °C followed by direct quenching using compressed and still air. The specimens were also isothermally quenched in salt bath at 200 and 300 °C for 2, 8, 30, and 120 min. Microstructures of the specimens were studied using optical microscope (traditional black and white etching as well as color etching), scanning electron microscope (SEM), microhardness tester, and X-ray diffraction (XRD). The results showed that the lowest amount of retained austenite in the microstructure was obtained in the specimens quenched isothermally at 300 °C for 120 min.

Key words

Cr-Mo steel austemperings martempering retained austenite microstructure 

References

  1. [1]
    Cleary P W. Recent Advances in DEM Modelling of Tumbling Mills [J]. Minerals Engineering, 2001, 14(10): 1295.CrossRefGoogle Scholar
  2. [2]
    Banisi S, Hadizadeh M. 3-D Liner Wear Profile Measurement and Analysis in Industrial SAG Mills [J]. Minerals Engineering, 2007, 20(2): 132.CrossRefGoogle Scholar
  3. [3]
    ASM M, et al. Handbook, Friction, Lubrication, and Wear Technology [M]. Ohio: American Society for Metals, 1992.Google Scholar
  4. [4]
    FU Han-guang, XIAO Qiang, FU Han-feng. Heat Treatment of Multi-Element Low Alloy Wear-Resistant Steel [J]. Materials Science and Engineering, 2005, 396A(1/2): 206.CrossRefGoogle Scholar
  5. [5]
    JIANG Zhi-qiang, DU Jian-ming, FENG Xi-lan. Study and Application of Heat Treatment of Multi-Element Wear-Resistant Low-Alloy Steel [J]. Journal of Iron and Steel Research International, 2006, 13(1): 57.MathSciNetCrossRefGoogle Scholar
  6. [6]
    Kim H J, Kweon Y G. The Effects of Retained Austenite on Dry Sliding Wear Behaviour of Carburized Steel [J]. Wear, 1996, 193(1): 8.CrossRefGoogle Scholar
  7. [7]
    Dhar N R, Kamruzzaman M. Cutting Temperature, Tool Wear, Surface Roughness and Dimensional Deviation in Turning AISI-4037 Steel Under Cryogenic Condition [J]. International Journal of Machine Tools and Manufacture, 2007, 47 (5): 754.CrossRefGoogle Scholar
  8. [8]
    Bain E C, Paxton H W. Alloying Element in Steel [M]. Ohio: American Society for Metals, 1970.Google Scholar
  9. [9]
    YANG Hong-shan, WANG Jun, SHEN Bao-luo, et al. Effect of Cryogenic Treatment on the Matrix Structure and Abrasion Resistance of White Cast Iron Subjected to Destabilization Treatment [J]. Wear, 2006, 261(10): 1150.CrossRefGoogle Scholar
  10. [10]
    Yakubtsov I A, Boyd J D. Bainite Transformation During Continuous Cooling of Low Carbon Microalloyed Steel [J]. Material Science and Technology, 2001, 17(3): 296.CrossRefGoogle Scholar
  11. [11]
    ZHAO Zhen-bo, LIU Cheng, LIU Yun-xun, et al. A New Empirical Formula for the Bainite Upper Temperature Limit of Steel [J]. Journal of Materials Science, 2001, 36(20): 5045.CrossRefGoogle Scholar

Copyright information

© China Iron and Steel Research Institute Group 2010

Authors and Affiliations

  • M. H. Shaeri
    • 1
  • H. Saghafian
    • 1
  • S. G. Shabestari
    • 1
  1. 1.School of Metallurgy and Materials EngineeringIran University of Science and TechnologyNarmak, TehranIran

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