高应变率下06Cr19Ni10奥氏体不锈钢Johnson-Cook本构模型研究

Research on Johnson-Cook constitutive model of 06Cr19Ni10 austenitic stainless steel at high strain rate

为了探讨06Cr19Ni10奥氏体不锈钢在大应变和高应变率下成形的流动规律,借助高温分离式霍普金森(High Temperature Split Hopkinson Pressure Bar)动态试验装置,进行不同温度和应变率冲击试验。分析试验数据表明,该材料具有增塑、应变率强化和温度软化现象,并建立了Johnson-Cook本构模型。考虑应变率强化效应,依据试验数据进行了JC本构模型的修正,对比修正前后模型预测值和试验值,吻合程度好。运用统计分析,对比修正前后模型的相关系数(R)和平均相对误差(AARE),修正前、后相关系数(R)分别为0.96388、0.97054;修正前、后平均相对误差(AARE)分别为5.63%、4.68%,修正后的模型预测精度优于修正前。结果表明,修正后的模型可以更加精确预测06Cr19Ni10奥氏体不锈钢应力与应变、应变率和温度的关系。

In order to explore the flow behavior of 06Cr19Ni10 austenitic stainless steel under large strain and high strain rate forming,impact tests had been carried out under different temperature and strain rate with the help of high temperature split hopkinson pressure bar dynamic experimental device.Impact test results show that the material has plasticization,strain rate strengthening and temperature softening phenomena,and the Johnson-Cook(JC)constitutive model has been established.Taking into account the strain rate strengthening effect the JC constitutive model was modified and both the model prediction values before and after the correction showed good agreement with experimental value.The correlation coefficients(R)before and after the model correction were 0.96388 and 0.97054,respectively,and the average relative error(AARE)before and after the correction were 5.63%,4.68%,respectively.This indicated that the revised model achieved better prediction accuracy than origin model.The revised model could be used to predict the relationship among stress,strain,strain rate and temperature of 06Cr19Ni10 austenitic stainless steel more accurately.