51CrV4轴箱弹簧钢的热处理工艺-组织-性能研究  

Correlation of Heat Treatment Process-Microstructure-Mechanical Properties of 51CrV4 Journal Box Spring

作　　者：徐超 王玉婷 曹欣旺 赵国亮 王晨阳 胡杰 许鑫 吕晶 杨其全 XU Chao;WANG Yuting;CAO Xinwang;ZHAO Guoiang;WANG Chenyang;HU Jie;XU Xin;LÜJing;YANG Qiquan(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;Beijing Advanced Material Technology Co.,Ltd.of CARS,Beijing 100081,China;Tianjin CRRC Equipment Co.,Ltd.,Tianjin 300232,China)

机构地区：[1]中国铁道科学研究院集团有限公司金属及化学研究所,北京100081 [2]北京中铁科新材料技术有限公司,北京100081 [3]天津中车机辆装备有限公司,天津300232

出　　处：《中国铁道科学》2024年第6期101-110,共10页China Railway Science

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(J2021J005)。

摘　　要：利用光学显微镜(OM)、场发射扫描电镜(FESEM)、万能拉力及旋转弯曲疲劳试验机,分析51CrV4弹簧钢在840~900℃淬火及380~520℃回火工艺下的组织性能演变规律,并对弹簧钢最佳性能的选择进行探讨,以确定51CrV4轴箱弹簧钢的适宜热处理工艺。结果表明:随着淬火温度的升高,51CrV4弹簧钢晶粒逐渐长大,组织奥氏体化及渗碳体溶解更充分,残留并遗传的块状铁素体及未溶颗粒状渗碳体减少,因此拉伸和疲劳强度升高,韧性和塑性下降;随着回火温度升高,马氏体向回火屈氏体的转变更充分,碳化物逐渐由针状长大成棒状或颗粒状,固溶强化和析出强化作用减弱,致使强度下降而韧性和塑性升高。鉴于实际服役中51CrV4弹簧失效较多且冲击韧性偏低的情况,弹簧钢应具有合理的强度与韧性匹配,则获得最优综合性能的热处理工艺范围为淬火900℃+回火460~480℃、淬火880℃+回火460℃,此时抗拉和屈服强度分别为1505~1551和1389~1430 MPa,冲击韧性为14.7~16.7 J。To study the optimum heat treatment process of 51CrV4 spring steel for high-speed trains,the microstructure and mechanical property changes of the steel under quenching temperatures ranging from 840-900℃and tempering temperatures from 380-520℃were analyzed using Optical Microscope(OM),Field Emission Scanning Electron Microscopy(FESEM),universal tensile and the rotating bending fatigue testing machine.The criteria for selecting the best performance of the spring steel of journal box were discussed to determine the suitable heat treatment process.The results show that with the increase of quenching temperature,the austenite grains of 51CrV4 gradually grow larger,the cementite dissolves more completely into the austenite,less blocky ferrites and undissolved granular cementites are remained,which result in the increase of tensile and fatigue strength,and the decrease of toughness and plasticity.With an increase in tempering temperature,the transformation from martensite to tempered troosite becomes more complete,and the carbide precipitate grows from needle-like to rod-like or granular shapes,solution strengthening and precipitation strengthening become weaker,which contributes to a decrease in strength and an increase in toughness and plasticity.Considering that the 51CrV4 journal box spring still has a higher failure rate and lower impact toughness,a reasonable strength-toughness matching should be achieved for 51CrV4 steel.Therefore,the optimum heat treatment process ranges for obtaining better comprehensive performances are quenching at 900℃followed by tempering at 460-480℃,quenching at 880℃followed by tempering at 460℃.The tensile and yield strength are 1505-1551 MPa and 1389-1430 MPa,respectively,and the impact toughness is 14.7-16.7 J.

关 键 词：热处理工艺 51CrV4钢 轴箱弹簧 组织性能 弹簧失效 

分 类 号：TG142.4[一般工业技术—材料科学与工程]