中文摘要：

为研究新型T91稀土钢的热力学性能,采用Gleeble-1500D热模拟试验机测定变形温度θ为1100~1250℃、ε觶为0.5~5 s-1时的应力-应变曲线,并采用Zener-Hollomon参数法构建该钢不同条件下高温塑性变形的本构方程。结果表明：在高变形温度及低应变速率时,测定的T91稀土钢应力-应变曲线呈双峰特征,有动态再结晶现象产生。随变形温度升高及应变速率的降低,动态再结晶现象越易发生;应变速率越小,流变应力下降越明显。T91钢的热变形激活能为509.04k J·mol-1。

英文摘要：

Hot compressive tests were carried out on Gleeble-1500 D thermal simulation test machine to investigate the hot deformation behavior of T91 rare-earth steel at temperatures 1100℃-1250℃ and strain rate of 0.5s-1-5s-1.The constitutive equation was constructed by introducing Zener-Hollomon parameter.The results show that,the true stress-true strain curves of T91 steel show a bimodal characteristic at high deformation temperature and low strain rate.Its mechanism is continuous dynamic recrystallization.With the deformation temperature increasing and strain rate decreasing,the dynamic recrystallization is easy to occur.With the strain rate decreasing,the flow stress decreases obviously.The deformation activation energy of the steel is 509.04 k J·mol-1.