60Si2CrVAT高强度弹簧钢的热压缩变形本构方程

摘要

The hot compression deformation of 60Si2CrVAT high-strength spring steel was carried out on thermo-simulation machine at different temperatures (900,950,1 050,1 150℃) and strain rates of 0.1-10 s-1, the influences of deformation temperature and strain rate on hot deformation behavior of the steel were investigated.The hot-compression deformation constitutive equation of 60Si2CrVAT spring steel was established based on hyperbolic sine equations of Arrhenius type.The results show that the flow stress of the spring steel increased with the increase of deformation rate and decreased with the increase of deformation temperature, it was found that dynamic recrystallization was more likely to occur at high deformation temperature and low strain rate.And the activation energy was calculated to be 372 kJ·mol-1 when true strain was 0.2, the calculated flow stress well agreed with the experimental results and the average relative error between them was 4.89%.%采用热模拟试验机对60Si2CrVAT高强度弹簧钢在不同温度(900,950,1 050,1 150 ℃)和应变速率下(0.1,1,5,10 s-1)进行热压缩变形,研究了变形温度和应变速率对该钢热变形行为的影响规律;在此基础上,根据Arrhenius双曲正弦方程,建立了该钢的热压缩变形本构方程.结果表明:该钢的流变应力随着变形速率的增大而增大,随变形温度的升高而减小,动态再结晶在高变形温度和低应变速率下更容易发生;真应变为0.2时的变形激活能为372 kJ·mol-1,流变应力的计算值与试验值之间的平均相对误差为4.89%,吻合得较好.