Effect of tempering temperature on the microstructure and properties of ultrahigh-strength stainless steel

作     者：Yangpeng Zhang Dongping Zhan Xiwei Qi Zhouhua Jiang 

作者机构：School of MetallurgyNortheastern UniversityShenyang110819China School of Materials Science and EngineeringNortheastern UniversityShenyang110819China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2019年第35卷第7期

页      面：1240-1249页

核心收录：

学科分类：0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported financially by the National Natural Science Foundation of China (Nos. 51874081 and 51574063) the Fundamental Research Funds for the Central Universities (Nos. N152306001 and N150204012) 

主　　题：Age hardening Austenite Precipitation Tempering Strengthening mechanism M7C3 

摘      要：The microstructure, precipitation and mechanical properties of Ferrium S53 steel, a secondary hardening ultrahigh-strength stainless steel with 10% Cr developed by QuesTek Innovations LLC, upon tem pering were studied by scanning electron microscopy (SEM), transm ission electron microscopy (TEM), X-ray diffraction (XRD), and tensile and impact tests. Based on these results, the influence of the tem pering temperature on the microstructure and properties was discussed. The results show th at decom position occurred when the retained austenite was tem pered above 440 ℃ and that the hardening peak at 482 ℃ was caused by the joint strengthening of the precipitates and martensite transformation. Due to the high Cr content, the trigonal M7C3 carbide precipitated w hen the steel was tem pered at 400 ℃, and M7C3 and M2C (5 -10 nm in size) coexisted w hen it was tem pered at 482 ℃. When the steel was tem pered at 630 ℃, M2C and M23C6 carbides precipitated, and the sizes w ere greater than 50 nm and 500 nm, respectively, but no M7C3 carbide formed. When the tempering tem perature was above 540 ℃, austenitization and large-size precipitates w ere the main factors affecting the strength and toughness.