45CrMo高强钢Hansel-Spittle本构模型的建立及验证

Establishment and verification of Hansel-Spittle constitutive model for 45CrMo high strength steel

使用Gleeble-3800热模拟实验机研究了45CrMo高强钢的高温力学行为。结果表明:在变形温度为800~1100℃、应变速率为0.01~10 s-1下,45CrMo高强钢真实应力随着真实应变的增加而先增大后减小,即同时出现了应变硬化和应变软化效应。对不同高温变形条件下的实验数据进行拟合,获得了Hansel-Spittle本构模型的相关参数。对45CrMo高强钢高温压缩性能在硬化阶段和软化阶段的Hansel-Spittle本构模型的预测值与实验值进行对比,结果表明:相同变形温度、不同应变速率以及相同应变速率、不同变形温度下的预测值和实验值的平均相对误差仅为0.04%,验证了Hansel-Spittle本构模型及其参数的有效性和正确性,尤其适用于高温变形时具有应变软化效应的材料。

The mechanical behavior at high temperature of 45 CrMo high strength steel was studied by Gleeble-3800 thermal simulation testing machine.The results show that under the deformation temperature of 800-1100℃and the strain rate of 0.01-10 s-1,the true stress increases firstly and then decreases with the increasing of true stain,that is,both strain hardening and strain softening effects appear.The relevant parameters in the Hansel-Spittle constitutive model were determined by fitting the experimental data under different high temperature deformation conditions.Compared the prediction value of Hansel-Spittle constitutive model for high temperature compression performance of 45 CrMo high strength steel in the hardening and softening stages with the experiment value,the results show that the average relative error between the predicted and experiment values is only 0.04%under the same deformation temperature and different strain rates or under the same strain rate and different deformation temperatures,which verifies the validity and accuracy of Hansel-Spittle constitutive model and its parameters.Especially,the Hansel-Spittle constitutive model is suitable to the material which has a strain softening effect during the high temperature deformation.