High Wear Resistance of White Cast Iron Treated by Novel Process: Principle and Mechanism
Based on microstructure desired, a novel process is proposed to treat Fe-2.4C-12.0Cr (mass pct) white cast iron balls, that is, destabilizing heat treatment following multicycle quenching and sub-critical treatment (De-MQ-Sct) process, and such a complex process is simply performed by alternate water quenching and air cooling. For comparison, the white cast iron balls also were treated by conventional normalization (NOR) process and Oil-quenching process, respectively. The partitioning of carbon from martensite to retained austenite during De-MQ-Sct process promotes the interaction between carbide precipitation and martensitic transformation, while this interaction is a unique effect only produced by multicycle quenching linking destabilizing and sub-critical treatments, which leads to more and finer secondary carbides and more carbon-enriched austenite in De-MQ-Sct sample than those in NOR or Oil-quenching sample. The average hardness of 60 HRC and impact toughness of 12.6 J/cm2 are obtained in De-MQ-Sct white cast iron balls, which are much higher than those in NOR and Oil-quenching ones. The wear behaviours measured by pin-on-disk wear tests indicate that the weight loss of De-MQ-Sct sample is only about one third of the NOR sample and one half of the Oil-quenching sample. Microstructural characterization reveals that high wear resistance related to hardness and toughness of the De-MQ-Sct balls are mainly attributed to the considerable fine secondary carbides and stable carbon-enriched retained austenite.
KeywordsAustenite Martensite Pearlite Martensitic Transformation Wear Surface
The work is financially supported by the National Natural Science Foundation of China (No. 51371117 and No. 51031001).
- 5.M. Janssen, M.B. Van Leeuwen, M.F. Mendes de Leon: Proceedings of the 14th European Conference on Fracture, A. Neimitz et al., eds., Emas Publications, London, 2002, pp. 617–25.Google Scholar
- 8.A. Bedolla-Jacuinde, M.W. Rainforth, I. Mejia: Metall Mater Trans A 2013; 44: 852-857.Google Scholar
- 16.Hakan Gasan, Fatin Erturk, Metall. Mater. Trans. A 44A(2013) 4493-5005.Google Scholar
- 32.Zhang K, Xu W Z, Guo Z H, Rong Y H, Wang M Q, Dong H. Acta Metall Sin, 2011; 47: 489.Google Scholar
- 34.Wang X D, Zhong N, Rong Y H, Xu Z Y. J Mater Res, 2009; 24: 261.Google Scholar
- 35.V.F. Zackay, E.R. Parker, D. Fahr, R. Busch, ASM Trans. Quart. 60 (1967) 252.Google Scholar
- 36.D. Webster, ASM Trans. Quart. 61(1968) 816.Google Scholar