Effects of Sub-zero Celsius Treatment and Tempering on the Stability of Retained Austenite in Bearing Steel
来源期刊:Acta Metallurgica Sinica2015年第6期
论文作者:Xiao-Hui Lu Wei Li Cheng-Lin Wang Hong-Shan Zhao Xue-Jun Jin
文章页码:787 - 792
摘 要:In this work, the influence of sub-zero Celsius treatment and tempering on the mechanical and thermal stability of retained austenite in bearing steel were assessed by tensile test and DSC. Compared with traditional quenched and tempered treatment, sub-zero Celsius treatment obviously decreases the volume fraction of retained austenite. Moreover,the mechanical stability of retained austenite was enhanced due to the accumulation of compressive stresses in retained austenite after sub-zero Celsius treatment and tempering. Meanwhile, the morphology of retained austenite changed from film-like to blocky with austenitization temperature increasing, and the mechanical stability of film-like retained austenite is higher than that of blocky one. The DSC results showed that the activation energy of retained austenite decomposition slightly increased through sub-zero Celsius treatment and tempering. This result may probably be ascribed to partitioning of carbon during tempering. However, the temperature at which retained austenite starts to decompose is unchanged.
Xiao-Hui Lu1,2,Wei Li2,Cheng-Lin Wang2,Hong-Shan Zhao2,Xue-Jun Jin1
1. State Key Lab of Metal Matrix Composite, School of Materials Science and Engineering, Shanghai Jiao Tong University2. Institute of Advanced Steels and Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University
摘 要:In this work, the influence of sub-zero Celsius treatment and tempering on the mechanical and thermal stability of retained austenite in bearing steel were assessed by tensile test and DSC. Compared with traditional quenched and tempered treatment, sub-zero Celsius treatment obviously decreases the volume fraction of retained austenite. Moreover,the mechanical stability of retained austenite was enhanced due to the accumulation of compressive stresses in retained austenite after sub-zero Celsius treatment and tempering. Meanwhile, the morphology of retained austenite changed from film-like to blocky with austenitization temperature increasing, and the mechanical stability of film-like retained austenite is higher than that of blocky one. The DSC results showed that the activation energy of retained austenite decomposition slightly increased through sub-zero Celsius treatment and tempering. This result may probably be ascribed to partitioning of carbon during tempering. However, the temperature at which retained austenite starts to decompose is unchanged.
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