新型CHDG-A06奥氏体不锈钢的热变形行为

摘要

Hot deformation behavior of new-typed CHDG-A06 austenitic stainless steel in temperature range of 950-1 100 ℃ and strain rate range of 0.01-1 s-1 was studied by single-pass compression test on a Gleeble-3500 thermal-mechanical simulator, and the steel's microstructure was observed.Based on stress and strain curves of the steel, high-temperature thermal deformation constitutive model was constructed through linear regression method.The results reveal that flow stress was sensitive to deformation temperature and strain rate during thermal deformation.The flow stress decreased with the increase of deformation temperature or the decrease of strain rate.The dynamic recrystallization was likely to occur at comparably lower strain rates(≤0.1 s-1) or higher deformation temperatures(≥1 050 ℃).The peak stress was used to attain the hyperbolic sine constitutive equation, and hot deformation activation energy of the steel was calculated to be 453.674 4 kJ·mol-1.%采用Gleeble-3500型热力模拟试验机对新型CHDG-A06奥氏体不锈钢进行单道次压缩试验,研究了其在变形温度为950~1 100 ℃、应变速率为0.01~1 s-1条件下的热变形行为,并对变形后的显微组织进行了观察;根据试验钢的应力-应变曲线,通过线性回归建立了它的高温热变形本构模型.结果表明:在热变形过程中,变形温度和应变速率对流变应力的影响显著,流变应力随着变形温度的升高或应变速率的降低而降低;动态再结晶易发生在较低应变速率(≤0.1 s-1)或较高变形温度(≥1 050 ℃)下;利用峰值应力求得该钢的双曲线正弦本构方程,并得到其热变形激活能为453.674 4 kJ·mol-1.