2Cr11Mo1VNbN钢再结晶动力学方程及本构方程的建立

Establishment of recrystallization kinetics equation and constitutive equation of 2Cr11Mo1VNbN steel

采用Gleeble-3800热模拟试验机,在温度为1 000~1 200℃、应变速率为0.01~1 s-1和变形量为70%的条件下研究了2Cr11Mo1VNbN钢的热变形行为,建立了动态再结晶型本构模型以及动态再结晶体积分数模型。结果表明:2Cr11Mo1VNbN钢在高温小应变速率的变形条件下易发生动态再结晶,计算得出2Cr11Mo1VNbN钢发生动态再结晶时的临界应变以及变形激活能并得到了动态再结晶体积分数模型,最终构建出的动态再结晶型本构方程能良好地描述2Cr11Mo1VNbN钢的高温流变行为。

The hot deformation behavior was investigated using the thermal simulation testing machine of Gleeble-3800 type in 2 Cr11 Mo1 VNbN steel. The experimental temperature was in the range of 1 000-1 200 ℃ and the strain rate changing from 0.01 s-1 to 1 s-1 with an ultimate deformation about 70%. Related models were established for dynamic recrystallization constitutive equation and dynamic recrystallization fraction. The experimental results indicate that the dynamic recrystallization can occur more easily under the conditions with higher temperature and lower strain rate. The critical strain and deformation activation energy for the occurrence of dynamic recrystallization in 2 Cr11 Mo1 VNbN steel were calculated and the dynamic curves reflecting the change process of recrystallization volume fraction were obtained. Ultimately, the dynamic recrystallization constitutive equation was established and it could properly describe rheological behavior of 2 Cr11 Mo1 VNbN steel at high temperature.