考虑变形热效应的本构关系建立方法

在等温恒应变速率压缩过程中，随着等效应变速率的增大，变形热效应对流动应力的影响程度增大。当等效应变速率很小时，变形热效应对流动应力的影响可忽略不计，压缩过程中可近似认为是等温过程；当等效应变速率较大时，变形热效应对流动应力的影响相当显著，压缩过程基本上成为绝热过程，提出了一种考虑变形热效应对流动应力影响的本构关系建立方法。用该方法建立的本构关系能客观地反映材料在热态变形过程中的动态响应特性，为提高

New method to establish constitutive relationship considering effect of deformation heating

During the isothermal constant strain rate compression process, the effect of deformation heating on flow stress increases with increasing equivalent strain rate. When the equivalent strain rate is relatively low, this influence can be neglected and the compression process can be considered as an isothermal process. While the equivalent strain rate is high, this influence is of importance and the compression process can be approximately considered as an adiabatic process. In this paper a method is proposed for taking the effect of deformation heating into consideration and the constitutive relationship for GH4169 alloy was formulated by using the method based on the results of isothermal constant strain rate compression test. The proposed constitutive relationship is capable of revealing the dynamical characteristics of materials during hot deformation processes, creating an essential prerequisite for improvement of numerical simulation accuracy of metal forming processes.