淬火温度对低钴二次硬化钢组织和性能的影响  

Effect of quenching temperature on microstructure and properties of a low cobalt secondary hardening steel

作　　者：熊金生 宁静[2] 苏杰[2] 姜庆伟[1] Xiong Jinsheng;Ning Jing;Su Jie;Jiang Qingwei(Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China;Research Institute of Special Steels,Central Iron and Steel Research Institute,Beijing 100081,China)

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院特殊钢研究院,北京100081

出　　处：《金属热处理》2022年第3期92-96,共5页Heat Treatment of Metals

摘　　要：采用Thermo-Calc热力学软件计算了一种新型低钴二次硬化钢高温区间的析出相种类和含量,结合光学显微镜、扫描电镜和力学检测等试验方法,研究了淬火温度对其组织和性能的影响。结果表明,在较低温度淬火时,板条马氏体基体上存在大量富W、Mo的球状M_(6)C析出相。升高淬火温度,M_(6)C相迅速回溶,并在1060℃时完全溶解。M_(6)C相的溶解使得二次硬化效果增强、冲击性能提升,同时导致原奥氏体晶粒明显粗化,进而对强韧性产生不利影响,最终试验钢经1060℃淬火后获得最佳力学性能配合。Types and contents of precipitated phases in the high temperature range of a new low cobalt secondary hardening steel were calculated by Thermo-Calc thermodynamic software.Combined with the experimental methods of optical microscope(OM),scanning electron microscope(SEM)and mechanical testing,the effect of quenching temperature on the microstructure and properties of the tested steel was studied.The results show that there are a large number of spherical W/Mo-rich M_(6)C precipitates on the lath martensite matrix when quenching at lower temperature.With the increase of quenching temperature,M_(6)C precipitates dissolves rapidly and completely dissolves at 1060℃.The dissolution of M_(6)C precipitates enhances the secondary hardening effect and improves the impact properties.At the same time,it causes the prior austenite grains to be significantly coarsened,which has an adverse impact on the strength and toughness.Finally,the tested steel obtains the optimal match of comprehensive mechanical properties after quenching at 1060℃.

关 键 词：二次硬化钢 淬火温度 力学性能 析出相 

分 类 号：TG156.3[金属学及工艺—热处理]