中文摘要：

利用Q550D超低碳贝氏体钢的热压缩试验数据建立了动态再结晶模型及元胞自动机模型,通过有限元软件DEFORM-3D对试样热变形过程的微观组织演变过程进行了模拟.结果表明：在变形温度为1 150°C条件下,当应变速率为0.05s-1时,热变形过程中的试样微观组织发生了动态再结晶现象,晶粒尺寸得到细化;在变形温度为1 050°C条件下,当应变速率不断增大时,奥氏体动态再结晶的晶粒尺寸减小;模拟结果与试验结果较吻合.

英文摘要：

The experimental data obtained by hot compression experiment were used to establish a Q550D low carbon bainite steel dynamic recrystallization model and a cellular automata model. The microstructure evolution on the hot deformation process was simulated by using DEFORM-3D finite element software. The simulation results show that the strain rate at a temperature of 1 150 ℃ for the 0.05 s-1 sample in the process of hot deformation microstructure have dynamic recrystallization and the grain size is refined. At a temperature of 1 050 ℃when the strain rate is increased, the dynamic recrystallization austenitic grain size decreases. The simulation results agrees with the experimental results.