二次回火对42CrMo4M钢组织性能的影响  

Effect of secondary tempering on microstructure and properties of 42CrMo4M steel

作　　者：梁雅鑫 蔡欣 郑雷刚[3] 胡小强 李殿中[2,3] LIANG Ya-xin;CAI Xin;ZHENG Lei-gang;HU Xiao-qiang;LI Dian-zhong(College of Rare Earth,University of Science and Technology of China,Ganzhou 341000,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341000,China;Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]中国科学技术大学稀土学院,江西赣州341000 [2]中国科学院赣江创新研究院,江西赣州341000 [3]中国科学院金属研究所沈阳材料科学国家研究中心,辽宁沈阳110016

出　　处：《材料热处理学报》2023年第8期106-114,共9页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2020YFB2006800);沈阳市中青年科技创新人才支持计划项目(RC220474);福建省科技计划STS配套项目(2021T0319);中国科学院战略性科技先导专项(XDC04000000)。

摘　　要：借助光学显微镜、扫描电镜、透射电镜和X射线衍射仪等研究了二次回火温度对42CrMo4M钢显微组织、力学性能和残余应力的影响。结果表明:二次回火后,42CrMo4M钢中马氏体板条进一步发生回复和再结晶,位错密度显著降低;长条状碳化物逐渐球化和粗化,转变为颗粒状形貌;随二次回火温度的升高,42CrMo4M钢的屈服强度和抗拉强度呈先上升后大幅下降的趋势,而塑韧性则变化较小。660℃二次回火后,42CrMo4M钢-20℃冲击吸收能量由调质处理后的111 J略微增加至120 J,增幅仅为9 J;此外,随着二次回火温度的升高,42CrMo4M钢中残余应力大致呈先下降后上升的趋势。640℃二次回火后,42CrMo4M钢中残余应力最低,为111.7 MPa,较调质处理后的152.5 MPa,降低了约26.75%。Effect of secondary tempering temperature on microstructure,mechanical properties and residual stress of 42CrMo4M steel was studied by means of optical microscope,scanning electron microscopy,transmission electron microscopy and X-ray diffractometer.The results show that after secondary tempering,the martensite lath in the 42CrMo4M steel further recovers and recrystallizes,and the dislocation density decreases significantly.The long strip shape carbides gradually spheroidize and coarsen,transforming into granular morphology.With the secondary tempering temperature increases,the yield strength and tensile strength of the 42CrMo4M steel show a trend of first increasing and then significantly decreasing,while the change in plasticity and toughness is relatively small.After secondary tempering at 660℃,the impact absorbed energy of the 42CrMo4M steel at -20℃ slightly increases from 111 J after quenching and tempering treatment to 120 J,with an increase of only 9 J.In addition,with the increase of secondary tempering temperature,the residual stress in the 42CrMo4M steel shows a trend of first decreasing and then increasing.After secondary tempering at 640℃,the residual stress in the 42CrMo4M steel is the lowest of 111.7 MPa,which is about 26.75% lower than that of 152.5 MPa after quenching and tempering treatment.

关 键 词：42CrMo4M钢 二次回火 力学性能 微观组织 残余应力 

分 类 号：TG142.3[一般工业技术—材料科学与工程]