Effects of Sub-zero Celsius Treatment and Tempering on the Stability of Retained Austenite in Bearing Steel  

作　　者：Xiao-Hui Lu Wei Li Cheng-Lin Wang Hong-Shan Zhao Xue-Jun Jin 

机构地区：[1]State Key Lab of Metal Matrix Composite, School of Materials Science and Engineering, Shanghai Jiao Tong University [2]Institute of Advanced Steels and Materials, School of Materials Science and Engineering, Shanghai Jiao Tong University

出　　处：《Acta Metallurgica Sinica(English Letters)》2015年第6期787-792,共6页金属学报（英文版）

基　　金：financially supported by the National Basic Research Program of China (No. 2011CB706604);National Natural Science Foundation of China (No. 51174251 and 51201105)

摘　　要：In this work, the influence of sub-zero Celsius treatment and tempering on the mechanical and thermal stability of retained austenite in beating 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.In this work, the influence of sub-zero Celsius treatment and tempering on the mechanical and thermal stability of retained austenite in beating 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.

关 键 词：Bearing steel Sub-zero Celsius treatment Retained austenite Stability 

分 类 号：TG161[金属学及工艺—热处理] TG156.5[金属学及工艺—金属学]