基于功热转换机理修正SUS301L-MT不锈钢J-C本构模型

Modified J-C Constitutive Model of SUS301L-MT Stainless Steel Based on Work-Heat Conversion Mechanism

在常温下对SUS301L-MT不锈钢进行了应变速率为0.0005 s^(-1)的准静态和0.1~500 s^(-1)的动态拉伸试验,基于经典J-C模型拟合得到其应力-应变曲线,通过最大拟合优度和匹配优度确定应变速率敏感系数,对经典J-C本构模型的模拟准确性进行分析;引入动态放大模量确定马氏体相变强化和绝热温升软化的临界应变,对J-C模型进行修正,并对修正模型的拟合结果进行了验证。结果表明:经典J-C本构模型无法准确描述试验钢在高应变速率塑性变形时的马氏体相变强化效应和绝热温升软化效应;修正后的J-C本构模型可准确描述应变速率在0.0005~500 s^(-1)时试验钢的力学行为,其匹配优度高达0.985,表明该模型合理有效。

Quasi-static tensile test with strain rate of 0.0005 s^(-1) and dynamic tensile tests with strain rates of 0.1—500 s^(-1) were carried out on SUS301 L-MT stainless steel at room temperature.The stress-strain curves of the stainless steel were obtained based on the classical J-C model fitting.The strain rate sensitivity coefficient was determined by the maximum fitting goodness and matching goodness,and the simulation accuracy of the classical J-C constitutive model was analyzed.The J-C model was modified by introducing the dynamic amplification modulus to determine the critical strain of martensitic transformation strengthening and adiabatic temperature rise softening,and the fitting results of the modified model were verified.The results show that the classical J-C constitutive model could not accurately describe the martensitic transformation strengthening effect and adiabatic temperature rise softening effect of test steel under high strain rate plastic deformation.The modified J-C constitutive model could accurately describe the mechanical behavior of the test steel when the strain rate was 0.0005—500 s^(-1),and its matching goodness was as high as 0.985,indicating that the model was reasonable and effective.