热锻过程中动态再结晶的数值模拟

在热锻过程中,由动态再结晶引起的微观组织演化是决定锻件最终性能的重要因素之一。基于更新的拉格朗日格式刚塑性有限元和考虑动态再结晶的粘塑性模型,建立了能够模拟变形过程、温度变化过程和动态再结晶过程的有限元方法,研制了轴对称有限元软件,并用该软件模拟26Cr2Ni4MoV小圆柱试样镦粗过程中由动态再结晶引起的微观组织演化。在软件中应用网格重新划分技术降低由于网格畸变引起的计算误差。模拟结果和实验结果符合良好。

NUMERICAL SIMULATION OF DYNAMIC DECRYSTALLIZATION DURING HOT FORGING

Microstructure evolution caused by dynamic recrystallization is one of the most important factors that determine the qualities of final forgings. Based on the rigid-plastic finite element theory and the viscoplastic model considering dynamic recrystallization, a finite element method is developed to simulate the deformation, temperature variation and microstructure evolution during hot forging. An axisymmetric finite element package for simulating the upsetting of cylindrical specimens is developed. Remeshing technique is introduced to decrease the error due to mesh distortion. Satisfactory agreements are reached between the simulated results and the experimental results, indicating that the present method can predict the microstructure evolution due to dynamic recrystallization during hot forging.