300M钢动态再结晶动力学

基于等温恒应变速率压缩实验,对300M钢在变形温度为850℃～1180℃、应变速率为0.01s-1～10s-1条件下的热变形行为,及其动态再结晶动力学行为进行研究。结果表明,当ln Z>33.37时,300M钢应力-应变曲线呈双峰不连续动态再结晶型,热变形过程发生两轮动态再结晶;当ln Z<33.37时,300M钢的应力-应变曲线呈单峰不连续动态再结晶型,热变形过程仅发生一轮动态再结晶。根据压缩实验结果,分别构建300M钢第一轮动态再结晶和第二轮动态再结晶的峰值应变、临界应变、平均晶粒尺寸和体积分数动力学模型。

Investigation on dynamic recrystallization kinetics of 300M steel

Based on the isothermal constant strain rate compression experiment,the hot deformation behavior and the dynamic recrystallization kinetics behavior of 300M steel in the deformation temperature range of 850℃~1180℃ and the strain rate range of 0.01s-1~10s-1 were researched.The results show that when the value of ln Z is more than 33.37,the stress-strain curves are the discontinuous dynamic recrystallization type with two peaks and there are two rounds of dynamic recrystallization during the hot deformation;when the value of ln Z is less than 33.37,the stress-strain curves are the discontinuous dynamic recrystallization type with one peak and there is only one round of dynamic recrystallization during the hot deformation.According to the data of the compression experiment,the kinetics mathematical models used to describe peak strain,critical strain,average grain size and volume fraction during the first and the second round of dynamic recrystallization of 300M steel were constructed.