双重淬火对EX1和8418模具钢组织和力学性能的影响  

Effect of double quenching on microstructure and mechanical properties of EX1 and 8418 die steel

作　　者：桑震 苏钰[1] 杨丽 许立然 雷佳乐 

机构地区：[1]上海工程技术大学材料工程学院,上海201600 [2]上海汇众汽车车桥系统有限公司,上海201800 [3]重庆优特模具有限公司,重庆400000

出　　处：《金属热处理》2017年第9期31-35,共5页Heat Treatment of Metals

基　　金：国家自然科学基金(51301105);上海工程技术大学研究生科研创新项目(15KY0518)

摘　　要：采用Thermo-calc软件对EX1模具钢和8418模具钢的相图进行模拟计算,根据相图辅助制定双重淬火工艺,并对EX1钢和8418钢进行热处理,利用光学显微镜及SEM对经过不同步骤热处理后的两种钢的组织及断口进行观察,并对两种钢的力学性能进行测试。结果表明,经过高温淬火处理后,两种钢的微观组织均为细小的板条状马氏体,回火处理后,转变为回火索氏体,经过二次淬火后,微观组织为粗大的板条状马氏体。经过热处理后的EX1模具钢硬度为433.2 HV50,略低于8418模具钢的472.0 HV50,但EX1模具钢的冲击性能和拉伸性能优于8418模具钢。The Thermo-calc software was applied to calculate the phase diagram of EX1 die steel and 8418 die steel, which applied to establish the double quenching process used for EX1 steel and 8418 steel. The microstructure and fracture of two kinds of steel were investigated systematically by OM and SEM, and the mechanical properties were tested. The results show that after high temperature quenching, the microstructure of the die steel is lath martensite, which changed to tempered sorbite after tempering. After the second quenching, the microstructure is coarse lath martensite. The hardness of EX1 steel is 433.2 HV50 after heat treatment, which slightly lower than 472.0 HV50 of the 8418 die steel, but the impact strength and tensile strength of EX1 steel are better than that of 8418 steel.

关 键 词：双重淬火 EX1钢 8418钢 组织结构 力学性能 

分 类 号：TG161[金属学及工艺—热处理]