TWIP钢高温变形行为的研究

通过单道次压缩试验,对Fe-Mn-C系孪生诱导塑性钢(TWIP钢),在800~1 000℃,应变速率0.01~10.0 s-1条件下的热变形行为及组织演变规律进行了研究.实验结果表明,升高温度和降低应变速率均可促进奥氏体发生动态再结晶.根据实验所得流变应力曲线,由热变形方程计算得到了TWIP钢热变形激活能Q=421.37 kJ/mol.并在此基础上得到了TWIP钢高温变形的热加工方程.采用Z参数预测了动态再结晶的临界条件,当Z≤9.94×1018时TWIP钢易发生动态再结晶,具有较好的热加工性能.

Investigation on Hot Workability Behavior of TWIP Steel

The hot deformation behavior of Fe-Mn-C twinning induced plasticity(TWIP) steel was investigated by hot compression tests in the temperature range of 800~1 000 ℃ and strain rate range of 0.01~10 s-1.Experimental results showed that increasing the temperature and decreasing strain rate promote the occurrence of dynamic recrystallization of austenite.According to the experimental flow stress curves,the hot working equation is obtained and the activation energy for plastic deformation is Q=421.37 kJ/mol.The occurrence of dynamic recrystallization can be estimated by using a Zener-Hollomon type equation and metallographic examination.Dynamic recrystallization is prone to occur when Z≤9.94×1018.The better hot deformation properties will be obtained under this condition.