20 A 钢热塑性变形的应力-应变本构模型研究

目的研究20A低碳钢在高温条件下的热变形行为及本构模型。方法采用Gleeble-1500型热模拟压缩试验,研究在不同变形温度及变形速率条件下,材料的真实应力-应变之间的关系。结果 20A钢属于对温度和应变速率都敏感的材料,其流变曲线呈现出周期性动态再结晶特征。结论通过对实验数据运用最小二乘法、多元线性回归方法及Arrhenius方程处理,得到了20A材料热变形本构模型为σ=8.8650ε0.1445ε·0.1283exp(3475.23/T),为20A钢塑性加工过程的控制及模拟提供了理论基础。

School of Material Science and Engineering,Chongqing University of Technology, Chongqing 400054, China

Objective With the purpose of studying the deformation behaviors and the constitutive model of 20A low-carbon steel under the condition of high temperature. Methods A hot compression test for 20A steel was performed by using Gleeble- 1500 thermal simulation- mechanical simulator under the condition of different deformation temperature and deformation rate to study the actual stress- strain relationship. Results The results showed that 20A steel was sensitive to the temperature and strain rate,and the rheological curves showed periodic characteristics of dynamic recrystallization. Conclusion The thermal deformation constitutive model（σ=8.8650ε0.1445ε·0.1283exp（3475.23/T）） of 20 A steel was established by numerical analysis,multivariate linear regression method and Arrhenius equation,which can provide guidance for the control and simulation of plastic deformation of 20A steel.