42CrMo环件锻轧成形-余热淬火全过程晶粒演化数值模拟与实验研究

Numerical simulation and experimental study on grain evolution in whole process of forging and rolling forming-waste heat quenching of 42CrMo ring

提出采用锻轧成形-余热淬火工艺实现40CrMo环件短流程低能耗绿色制造,其中组织性能调控是关键问题。通过模拟与实验研究了42CrMo环件下料-制坯-热轧-余热淬火全过程中的晶粒演化规律。基于Abaqus有限元分析软件建立了42CrMo环件从下料到余热淬火的宏微观耦合三维有限元模型,发现余热淬火后的环件平均晶粒尺寸分布与实验结果吻合较好。研究了环件成形全过程中的晶粒演化规律和温度分布对平均晶粒尺寸的影响规律、余热淬火过程中平均晶粒尺寸的变化以及轧制时间及下料温度对平均晶粒尺寸的影响规律。结果表明:在余热淬火过程中,环件心部的晶粒粗化现象较为明显,表面不明显。降低下料温度和增加轧制时间可以减小环件心部温度,使心部晶粒粗化程度降低,进而改善表层和心部晶粒尺寸的差异。

Forging and rolling forming-waste heat quenching process was put forward to achieve green manufacturing with short process and low energy consumption of 40CrMo ring,in which the key problem is the regulation of organization and performance.The grain evolution law of 42CrMo ring in the whole process of blanking-billet making-hot rolling-waste heat quenching was studied by simulation and experiment.Based on the Abaqus finite element analysis software,the three-dimensional finite element model of macro and micro coupling of 42CrMo ring from blanking to waste heat quenching was established.It is found that the average grain size distribution of the ring after waste heat quenching is in good agreement with the experimental result.The evolution law of grain,the influence law of temperature distribution on average grain size in the whole ring forming process,the change of average grain size in the process of waste heat quenching,and the influence law of rolling time and blanking temperature on average grain size were studied.The results show that in the process of waste heat quenching,the grain coarsening phenomenon in the center of ring is obvious,while it is not obvious on the surface.Decreasing the blanking temperature and increasing the rolling time can reduce the temperature in the center of ring,reduce the grain coarsening degree in the center,and then improve the difference of grain size between the surface layer and center.