奥氏体变形对40CrNi4MoV钢连续冷却相变行为的影响  

Effect of austenite deformation on continuous cooling transformation behavior of 40CrNi4MoV steel

作　　者：王剑龙 周乐育 白玉洁 蒋波[1] 吴鉴喆 王若宇 Wang Jianlong;Zhou Leyu;Bai Yujie;Jiang Bo;Wu Jianzhe;Wang Ruoyu(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;China Academy of Machinery Beijing Research Institute of Mechanical&Electrical Technology Co.,Ltd.,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]中国机械总院集团北京机电研究所有限公司,北京100083

出　　处：《锻压技术》2025年第3期30-39,共10页Forging & Stamping Technology

基　　金：国防基础科研计划(JCKY2022208A002)。

摘　　要：通过热模拟实验、光学显微镜和扫描电子显微镜观察以及维氏硬度测试,研究了40CrNi4MoV钢的动态和静态奥氏体连续转变规律,分析了变形对40CrNi4MoV钢奥氏体转变行为的影响。结果表明:奥氏体变形促进了40CrNi4MoV钢连续冷却马氏体相变,使贝氏体转变区间缩小,全马氏体临界冷却速度由1℃·s^(-1)降低至0.5℃·s^(-1)。低冷却速度(0.05~0.3℃·s^(-1))下40CrNi4MoV钢组织主要为马氏体和贝氏体。在动态CCT中,冷却速度为0.5℃·s^(-1)时,形成全马氏体,显微硬度为621 HV;在静态CCT中,冷却速度为1℃·s^(-1)时,形成全马氏体,显微硬度为600 HV。经过奥氏体变形再结晶,冷却后形成的马氏体明显细化,位错密度明显提高,进而提升其显微硬度。奥氏体变形使得马氏体开始转变温度降低约20℃。The dynamic and static austenite continuous transformation laws of 40CrNi4MoV steel were investigated by thermal simulation experiment,optical microscopy,scanning electron microscope observation and Vickers hardness test,and the influence of deformation on the austenite transformation behavior of 40CrNi4MoV steel was analyzed.The results indicate that austenite deformation promotes the continuous cooling martensitic transformation of 40CrNi4MoV steel,the bainite transformation range is narrowed,and the critical cooling rate for fully martensite is reduced from 1℃·s^(-1) to 0.5℃·s^(-1).At low cooling rate(0.05-0.3℃·s^(-1)),the microstructure of 40CrNi4MoV steel is mainly martensite and bainite.In dynamic CCT,full martensite is formed at a cooling rate of 0.5℃·s^(-1),and the microhardness is 621 HV.In static CCT,full martensite is formed at a cooling rate of 1℃·s^(-1),and the microhardness of 600 HV.After austenite deformation and recrystallization,the martensite formed after cooling is significantly refined,and its dislocation density is significantly increased,thereby improving its microhardness.The austenite deformation reduces the martensite transformation temperature by about 20℃.

关 键 词：40CrNi4MoV钢 CCT曲线 显微组织 硬度 马氏体相变 贝氏体相变 

分 类 号：TG151.2[金属学及工艺—热处理] TG111.5[金属学及工艺—金属学]