基于修正Johnson-Cook模型的HNi56-3镍黄铜合金高温流变行为研究

Research on high-temperature rheological behavior for HNi56-3 nickel brass alloy based on modified Johnson-Cook model

以HNi56-3镍黄铜合金为研究对象,分别在变形温度范围为600~800℃、应变速率范围为0.01~10 s^-1的变形条件下,在Gleeble-3500热模拟实验机上进行等温热压缩实验,研究HNi56-3镍黄铜合金的高温流变行为。实验结果表明:HNi56-3镍黄铜合金的流变应力与变形温度、应变速率和应变呈非线性关系,流变应力随着应变速率和应变的增大而升高、随着变形温度的升高而降低。为了描述HNi56-3镍黄铜合金的流变行为,使用Lin Y C修正的Johnson-Cook模型(Lin-JC)和本文修正的JC模型(MLin-JC)分别建立本构模型。对比两种模型,结果显示:基于Lin-JC模型的预测数据的平均相对误差绝对值AARE为11.8644%,相关系数R为0.9803,均方根误差RMSE为4.6177 MPa;本文构建的MLin-JC模型的预测数据的AARE为4.0325%,R为0.9936,RMSE为1.9017 MPa,因此,本文建立的本构模型与实验结果更吻合,能更准确地描述HNi56-3镍黄铜合金的高温流变行为。

For HNi56-3 nickel brass alloy,the isothermal thermal compression experiments were conducted by Gleeble-3500 thermo-mechanical simulator under the deformation temperatures of 600-800℃and the strain rates of 0.01-10 s^-1,and the high-temperature rheological behavior of HNi56-3 nickel brass alloy was studied.The experimental results show that the rheological stress of HNi56-3 nickel brass alloy has a nonlinear relationship with deformation temperature,strain rate and strain,and the rheological stress increases with the increasing of strain rate and strain,and decreases with the increasing of deformation temperature.In order to describe the rheological behavior of HNi56-3 nickel brass alloy,the constitutive models were established by Lin-JC model modified by Lin Y C and Mlin-JC model modified by this paper.Comparing two models,the results show that the absolute value of average absolute relative error AARE of prediction data based on Lin-JC model is 11.8644%,the correlation coefficient R is 0.9803,and the root mean squared error RMSE is 4.6177 MPa.However,the corresponding values of AARE,R and RMSE based on MLin-JC model are 4.0325%,0.9936 and 1.9017 MPa respectively.Thus,the prediction accuracy based on MLin-JC model is better,and the MLin-JC model can accurately describe the high-temperature rheological behavior of HNi56-3 nickel brass alloy.