考虑TRIP效应的0.1C-5Mn中锰钢本构关系研究

Study on constitutive relation of 0.1C-5Mn medium manganese steel considering TRIP effect

通过XRD试验获得了中锰钢板材在单向拉伸状态下奥氏体转变与应变之间的规律,中锰钢中的残余奥氏体体积分数随应变量的增加呈现出非线性下降趋势。由马氏体相变动力学模型得出了中锰钢中的残余奥氏体与等效塑性应变之间的函数关系。根据中锰钢的微观结构特点和细观力学方法,建立了包含TRIP效应的中锰钢本构模型,在该本构模型中考虑了马氏体转变与应力平衡对应力应变关系的影响。将塑性流动法则和等效夹杂方法在ABAQUS的UMAT子程序中实现,编写了UMAT子程序,最后输出了中锰钢的应力-应变流动曲线,并通过与试验得到的曲线进行对比验证了该方法的准确性。

The regularity between the austenite transformation and strain of medium manganese steel sheet under uniaxial tension was obtained through XRD test.The residual austenite volume fraction in medium manganese steel shows a non-linear downward trend with the increase of strain.According to the martensitic transformation kinetic model,the function relationship between residual austenite and equivalent strain in medium manganese steel was deduced.According to the microstructure characteristics and mesomechanics method of medium manganese steel,the constitutive model of medium manganese steel considering TRIP effect was established.The influence of martensite transformation and stress balance on the stress-strain relationship was considered in the constitutive model.The plastic flow law and the equivalent inclusion method were implemented in the UMAT subroutine of ABAQUS,the UMAT subroutine was written,and finally the stress-strain flow curve of the medium manganese steel was output.The accuracy of the method was verified by comparing with the curve obtained by the experiment.