基于MATLAB的铸态C19400合金高温变形行为及本构方程

High temperature deformation behavior and constitutive equation of as-cast C19400 alloy based on MATLAB

通过Gleeble-1500D数控动态热-力学模拟试验机对铸态C19400合金进行了高温等温热压缩试验,研究了该合金在变形温度700~950℃,应变速率0.001~10 s-1条件下的高温变形行为。结果表明:在同一应变速率下,铸态C19400合金的流变应力随温度的升高而降低,在同一变形温度下,合金流变应力随应变速率的升高而升高。应变速率为0.001、0.01、0.1和1 s-1时,动态软化以动态回复为主;应变速率为10 s-1时,动态软化以动态再结晶为主,且再结晶程度随变形温度的升高而增加。此外,本文提出了一种基于MATLAB平台编程计算本构方程的方法,得到了基于Arrhenius双曲正弦本构关系的铸态C19400合金峰值流变应力本构方程,并计算得到该本构方程计算应力与试验应力的相对误差AARE为2.71%、相关系数R为0.9977,表明计算结果与试验结果高度吻合。

The high temperature isothermal compression test of as-cast C19400 alloy was carried out by Gleeble-1500 D numerical control dynamic thermomechanical simulation tester.The high temperature deformation behavior of the C19400 alloy was studied under the conditions of deformation temperature of 700-950℃and strain rate of 0.0001-10 s-1.The results show that the flow stress of the as-cast C19400 alloy decreases with the increase of temperature at the same strain rate,and increases with the increase of strain rate at the same deformation temperature.When the strain rate is 0.001,0.01,0.1 and 1 s-1,the dynamic softening is mainly dynamic recovery,and when the strain rate is 10 s-1,the dynamic softening is mainly dynamic recrystallizing,and the degree of recrystallizing increases with the increase of deformation temperature.In addition,a method of calculating the constitutive equation based on MATLAB platform is presented in this paper,and the peak flow stress constitutive equation of the as-cast C19400 alloy based on Arrhenius hyperbolic sinusoidal constitutive relation is obtained,the relative error between the calculated stress and the experimental stress is 2.71%and the correlation coefficient R is 0.999,which shows that the calculated results are in good agreement with the experimental results.