基于改进J-C模型的42CrMo钢动态本构关系研究  

Study on Dynamic Constitutive Relation of 42CrMo Steel Based on Johnson-Cook Model

作　　者：卢也森 朱志武[1] 谢奇峻 

机构地区：[1]西南交通大学力学与工程学院,成都610031

出　　处：《四川理工学院学报（自然科学版）》2016年第3期61-65,共5页Journal of Sichuan University of Science & Engineering(Natural Science Edition)

基　　金：国家自然科学基金项目(11172251);四川省青年科技创新团队(2013TD0004)

摘　　要：42CrMo钢作为高速列车车轴的主要原材料,在高速列车运营中承受复杂的载荷条件。其中除了正常的设计载荷之外,还将承受不同程度的冲击载荷作用。为研究车轴钢的动态力学性能及其应力-应变关系,对42CrMo钢进行准静态及动态压缩力学性能实验,得到42CrMo钢在10-3～5000区间内七个应变率下的应力-应变曲线,结果显示42CrMo钢在高应变率下无明显应变率相关性,存在热软化效应。热软化效应被认为是在高速冲击下,材料塑性变形产生的热量无法向外界快速扩散从而积累导致温度上升而造成。采用改进J-C模型,考虑绝热温升影响,对材料进行本构描述,结果显示改进J-C模型在描述及预测不同应变率下42CrMo钢的流动应力时表现很好。42CrMo steel,as the main raw material of the high-speed train axles,withstands complex loading conditions in the high-speed train. Whereas axle is an essential component,in addition to considering the normal design loads,the effect of the impact load need to be considered more specifically. In order to study the dynamic mechanical properties and stress-strain relationship of steel axle,the quasi-static and dynamic compression of 42 Cr Mo steel were tested. Seven experiments at strain rates ranging from 10～（-3）s～（-1） to 5000s～（-1） show thermal softening exists without rate-dependent plastic behavior.Because of the high impact speed,the plastic deformation is carried out with no heat,then the temperature rises by accumulating. And a new constitutive model which includes thermal softening effect based on the J-C constitutive model has been proposed to describe the dynamic mechanical behavior of 42 CrMo steel. They are in good agreement with the experimental data,which show that the new constitutive model can describe the mechanical behavior of 42 CrMo steel at various strain rates very well.

关 键 词：42CRMO钢 分离式霍普金森压杆 热软化效应 J-C模型 

分 类 号：O347.1[理学—固体力学]