Finite element study on microstructure evolution and grain refinement in the forging process of automotive front axle beam

Abstract

Combined with the recrystallization models, a 3D thermo-mechanical coupling finite element model is established to predict the microstructure evolution in the automotive front axle beam during the hot forging processing. It attempted to reveal the relationship between the forging processing and microstructure evolution. The numerical results show that after forging the average temperature of billet is higher than 850°C, indicating that the front axle beam is formed above the final forging temperature. During each step of forging process, the strain mainly takes place at the segment of billet with larger plastic deformation, indicating an evident recrystallization phenomenon. The initial average grain size of the billet is about 150μm, while after forming, it will be refined to almost 45μm due to the dynamic recrystallization. The established 3D FE model coupling the recrystallization models can provide a theoretical guidance for optimizing the forging processing parameters of automotive front axle beam.