Numerical modeling of dynamic recrystallization during nonisothermal hot compression by cellular automata and finite element analysis

摘要

In this study, dynamic recrystallization during nonisothermal hot compression was numerically simulated by cellular automata and finite element analysis. A modified cellular automata model was developed by introducing a new parameter for considering solute drag effect. The isothermal hot compression tests of pure copper were carried out to verify the modified cellular automata model by comparing material behavior and average grain size. The effect of solute drag was numerically considered and compared to the experimental data and the numerical data obtained by conventional cellular automata without solute drag effect. Then, the modified cellular automata model was applied to a nonisothermal hot compression by combining with a finite element analysis. The finite element analysis was conducted to acquire local parameters such as strain, strain rate, and temperature. These values were provided to the cellular automata model as input. The local changes of microstructure and average grain size were simulated by cellular automata and compared with nonisothermal hot compression results. The simulation results were in reasonably good agreement with experimentally determined microstructures by electron backscattering diffraction. The developed model was further applied to simulate a hot gear blank forging process to check its applicability. With the current approach, local microstructures can be determined for better understanding microstructural changes during the nonisothermal process.