20Cr2Ni4A钢高温变形行为及物理基参数本构模型

Elevated temperature deformation behavior and physically-based parameter constitutive model of 20Cr2Ni4A steel

采用Gleeble-3500热模拟试验机,在变形温度1073.15~1273.15K,应变速率0.001~1s^-1。下进行了20Cr2Ni4A钢的等温压缩试验。结果表明,20Cr2Ni4A钢的流变应力随变形速率的增加或变形温度的降低而增加。基于峰值应力,分别采用表征参数和物理基参数构建了20Cr2Ni4A钢的Arrhenius型本构模型。结果表明,两种本构模型对峰值应力均具有良好的预测精度。通过对比分析考虑应变影响的两种本构模型,研究了两种本构模型在整个应变范围的预测能力。结果表明,在低应变区,表征参数本构模型的预测值更接近实测值。达到峰值应变后,物理基参数本构模型的预测值与表征参数本构模型的预测值十分接近,均能提供较高的预测精度。

The isothermal compression tests of20Cr2Ni4A steel were implemented on Gleeble-3500 thermal simulation machine at de- formation temperatures of 1073.15-1273.15K and strain rates of 0.001-1s^-1.The results show that the flow stress of 20Cr2Ni4A steel increases with the increase of deformation rate or the decrease of deformation temperature.The Arrhenius-type constitutive models of 20Cr2Ni4A steel were derived by using apparent parameter and physically-based parameter respectively based on peak stress.The results show that the two constitutive models both have satisfactory prediction accuracy.The predictive ability of the two kinds of constitutive models in the entire strain range was investigated through comparative analysis of the two kinds of constitutive models which considering the effect of strain.The results indicate that the predicted values of apparent parameter constitutive model are much closer to the measured values in the low strain zone.After reaching the peak strain,the predicted values of physically-based parameter constitutive model are close to the predicted values of apparent parameter constitutive model,and both can provide high prediction accuracy.