表征动态回复的22MnB5钢高温变形本构模型研究

Research on High Temperature Deformation Constitutive Model of 22MnB5 Steel for Characterizing Dynamic Recovery

通过对22MnB5钢板在不同应变速率和变形温度下进行Gleeble高温拉伸试验,对试验数据进行真应力应变换算获得了真应力-应变曲线,并对曲线进行了分析。通过引入Zener-Hollomon参数的位错密度演化模型描述加工硬化和动态回复对流动应力的影响,并建立包含稳态应力、屈服应力和动态回复速率系数r这3个参数的本构模型。结果表明:该本构模型获得的计算值与试验值吻合度较高,具有一定的指导实践作用。

The Gleeble high-temperature tensile experiment was performed on 22MnB5 steel plate at different strain rates and deformation temperatures.The true stress-strain curve was obtained by converting the experimental data to true stress and strain,and the curve was analyzed.The dislocation density evolution model of the Zener-Hollomon parameter is introduced to describe the effect of work hardening and dynamic recovery on flow stress,and a constitutive model including three parameters of steady-state stress,yield stress and dynamic recovery rate coefficient r is established.The results show that the calculated value obtained by the constitutive model is in good agreement with the experimental value,and has a certain guiding practical effect.