基于热力耦合的42CrMo支撑座成形动态再结晶模拟分析

Numerical Simulation on Dynamic Recrystallization in Supporting Pedestal Forging of 42GrMo Based on Thermal-mechanical Coupling

在综合考虑了成形、热传导、产热及动态再结晶的情况下,采用了刚粘塑性有限元与动态再结晶演化热力耦合的方法,建立了宏观与微观相结合的工艺模型,对42CrMo钢支撑座进行了锻造过程变形和动态再结晶的热力耦合模拟。结果表明:在宏观上,支撑座制件成形良好;从微观角度分析,晶粒尺寸介于18.6～22.1μm的金属所占体积百分比最大,为28.962%;约有67.244%的金属发生了完全动态再结晶。此外还分析了该锻件的一个重要受力截面,该截面内部晶粒尺寸较锻件顶部与底部的晶粒尺寸略大些,这是由于内部长时间高温使得晶粒二次长大。

Combining formation,heat transfer,heating generation and dynamic recrystallization,a rigid visco-plastic finite element method and dynamic recrystallization coupled thermo-mechanical method was adopted to set up a macro-micro coupled model,and the deformation and dynamic recrystallization of the thermo-mechanical coupling in the forming process for 42CrMo supporting pedestal was simulated.The results show that the supporting pedestal is formed well at macro level;at micro-level,the grains in 18.6～22.1 μm take up the most percentage,which is 28.962%;about 67.244% metal get a complete dynamic recrystallization in the forming process.Meanwhile,an important force＇s cross-section is analyzed,it is showed that the size of the internal grain is larger than that of the top and bottom zone,the reason is that a long time internal heat makes the grain grow secondly up.