(西北工业大学 材料科学与工程学院， 西安 710072)
摘 要: 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，为提高塑性加工过程数值模拟的精度创造了必要的前提。
关键字: 本构关系； 变形热效应； 非线性回归； 热力参数
（College of Materials Science & Engineering， Northwestern Polytechnical University Xi′an 710072， P.R.China）
Abstract:During the isothermal constant strain rate compression process, the effectof deformation heating on flow stress increases with increasing equivalent strain rate. When the equivalent strain rate is relatively low， this influence can beneglected 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 isothermalconstant 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.
Key words: constitutive relationship； deformation heating； nonlinear regression； thermomechanical parameters
