Impact of Original Micro-Structure on Grind-Hardened Layer of 42CrMo Steel in Grind-Hardening

Abstract:

The grind-hardening test of 42CrMo steel was carried out on a forming grinding machine. The macrostructure, microstructures, micro-hardness and the depth of the hardened layer were measured and analyzed by optical micro-scope, scanning electron microscope and digital micro-hardness tester. The influences of original microstructure on the grind-hardened layer of 42CrMo steel were studied. The results show that the acicular martensite and a small amount of undissolved carbide appear in the surface layer, and slightly coarse martensite and a small amount of undissolved carbide appear in the middle layer of the completely hardened zone. Microstructure of the transitional zone varies with original structure. The microstructures and micro-hardness of the completely hardened zone have no obvious change under different original organizations, and the micro-hardness is 620HV0.5-700HV0.5. However, the distance from the slightly coarse martensite and the depth of the hardened layer increase with the uniformity improvement of the original microstructure.

• Periodical: Materials Science Forum (Volume 878)
• Pages: 22-27
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.878.22
• Online since: November 2016
• Authors: Gui Cheng Wang, Bin Jiao, Jun Feng Zou, Hong Jie Pei*
• Keywords: Depth of Hardened Layer, Grind-Hardening, Micro-Hardness, Micro-Structure, Original Micro-Structure

References

[1] Brockhoff T. Annals of the CIRP, 1999, 48(1): 255- 260.

[2] Zarudi I, Zhang L C. Journal of Materials Science, 2002, 37(18): 3935- 3943.

[3] Fricker D C, Pearce T, Harrison A. Journal of Engineering Manufacture, 2004, 218(10): 1339- 1356.

[4] Chryssolouris G, Tsirbas K, Salonitis K. Journal of Manufacturing Process, 2005, 7(1): 1- 9.

[5] Nguyen T, Zarudi I, Zhang L C. International Journal of Machine Tools and Manufacture: 2007, 47(1): 97- 106.

[6] Ju-Dong LIU. Studies on the Forming Mechanism of the Grinding-Hardening and Its Application Fundament, (D). Jiangsu University, Zhenjiang, China, 2005. (In Chinese).

[7] Ke-Ming LIU, Zhuang MA, Lian-Yong Zhang. et al. Materials for Mechanical Engineering, 2012, 36(5): 58-61. (In Chinese).

[8] Zhuang Ma, Bo LIU, Hai-Fang SHI, et al. Material Science and Engineering, 2011, 34(5): 26-28. (In Chinese).

[9] Ke-Ming LIU, Zhuang MA, Lian-Yong Zhang. et al. Material & Heat Treatment, 2012, 41(14): 215-217. (In Chinese).

[10] Ke-Ming LIU, Bo LIU, Zhuang MA, et al. Material & Heat Treatment, 2012, 41(12): 196-198. (In Chinese).

[11] Ju-Dong LIU, Gui-Cheng WANG, Kang-Ming CHEN, et al. China Mechanical Engineering, 2005, 16(11): 1013-1017. (In Chinese).