95CrMo钢高温流变应力的本构方程

Constitutive equation for high temperature flow stress of 95CrMosteel

采用Gleeble3500热模拟试验机对95CrMo钢进行了等温单向热压缩试验,得到了其在应变速率为0.1、1和10 s-1,变形温度为750~1050℃时的流变应力曲线。结果表明,应变量、变形温度和应变速率对95CrMo钢流变应力的影响是通过动态回复和动态再结晶软化机制造成的,这种软化机制是三者共同作用的结果。基于试验结果,建立了一种同时考虑应变量补偿、变形温度补偿和应变速率补偿的95CrMo钢流变应力本构方程。从相关系数、平均相对误差和标准偏差3个方面将该方程与周纪华-管克制模型进行了对比,发现该本构方程相比周纪华-管克智模型具有更高的精度和可靠性,更适用于数值仿真领域。

The flow stress curve of 95 CrMo steel was studied by isothermal unidirectional heat compression test at 750-1050 ℃ with strain rates of 0. 1,1 and 10 s-1using Gleeble-3500 thermal-simulation machine. The results show that the influence of strain degree,deformation temperature and strain rate on the flow stress of 95 CrMo steel is caused by dynamic recovery and dynamic recrystallization softening mechanism which is the result of the joint action of these three factors. According to the experimental results,a constitutive equation of flow stress of 95 Cr Mosteel is established,which take the compensation of strain degree,deformation temperature and strain rate into account simultaneously. The correlation coefficient,average relative error and standard deviation of this equation are compared with that of the model of Zhou Jihua-Guan Kezhi. The results show that this constitutive equation is more accurate and more reliable than the model of Zhou Jihua-Guan Kezhi,it is more suitable for the numerical simulation field.