9Cr低活化马氏体钢高温变形行为

采用Gleeble-1500D热模拟试验机研究了9Cr低活化马氏体钢在950~1200℃、应变速率为10^-2~10s^-1变形条件下的热压缩变形行为,并用金相显微镜观察了相应显微组织的变化.回归分析得出在0.15~0.8真应变量范围内变形激活能和材料常数随真应变量变化的关系式,并得出双曲正弦本构方程;利用数学方法直接从真应力-真应变曲线获得动态再结晶的峰值应力、临界应力、峰值应变和临界应变;回归得出了峰值应力、临界应力、峰值应变、临界应变和动态再结晶晶粒大小与Zener-Hollomon参数的关系式.

Hot deformation behavior of 9Cr reduced activation martensitic steel

The hot deformation behavior of 9Cr reduced activation martensitic steel was investigated by compression testing on a Gleeble-1500D simulator in the temperature range of 950 to 1200℃ and the strain rate range of 10^-2 to 10 s^-1, and the microstructural evolution was analyzed by metallography. Based on measured data in the strain range of 0.15 to 0.8, material parameters in the Arrhenius-type hyperbolic-sine equation were solved by using regression analysis methods and then used to fit the deformation. A constitutive equation which relates the flow stress to temperature, strain rate and strain was established by mathematical methods. The values of peak stress, critical stress, peak strain, critical strain and grain size for dynamic recrystallization (DRX) were determined from the true strain-true stress curves and their equations related to the Zener-Hollomon parameter were obtained.