两种连续局部塑性成形工艺对锻件微观组织的影响

Effects of two successively and locally plastic forming processes on microstructure

通过模拟分析与实验分析结合的方法,验证连续局部塑性成形微观组织演变有限元模型的正确性,采用该模型对42CrMo钢坯料辊锻过程中的组织晶粒度进行预报,研究42CrMo钢辊锻过程的奥氏体晶粒尺寸演化规律;对楔横轧变形过程中组织晶粒度变化进行研究,并对两种连续局部塑性成形后锻件组织晶粒度进行对比。研究结果表明,辊锻变形坯料P1、P2、P3处奥氏体晶粒尺寸实验结果与有限元预报结果吻合良好,晶粒尺寸变化为动态再结晶细化;楔横轧变形过程中,动态再结晶和奥氏体晶粒长大作用同时发生;通过对两种连续局部塑性成形得到的锻件微观组织进行比较,楔横轧锻件整体平均晶粒尺寸更加细小、均匀。

By using the physical experiments, the finite element model （FEM） for microstructure evolution prediction in succes-sively and locally plastic forming processes was verified. This model was used for simut, ating the grain size of 42CrMo steel duringthe roll forging process, and the evolvement rules of the austenite grain size were analyzed during this process. Also, the microstructure evolution in cross wedge rolling was researched, and the grain sizes of these two plastic forming processes were com-pared. The research shows that the predicted austenite grain sizes at point P1, P2, P3 agree well with the experimental data forroll forging, and the grain sizes are refined due to dynamic recrystallization. During cross wedge rolling process, both the aus-tenite dynamic reerystallization and grain growth effects occur simultaneously. By comparing the microstructure of these two suc-cessively and locally plastic forming processes, the overall average grain size of wedge rolling forging is finer and more uniform.