Prediction of microstructure evolution of 316ln austenitic stainless steel using cellular automata and a novel evaluation method for grain size inhomogeneity

Inhomogeneous grain size is a significant structural defect in large forgings. This study employed cellular automata to simulate the dynamic recrystallization (DRX) of 316LN steel and analyzed the grain distribution during DRX. The accuracy of the CA method was verified by comparing its results with the results of a thermal simulation test on Gleeble 1500D. Subsequently, a novel method for evaluating grain size inhomogeneity was proposed. The grain size inhomogeneity coefficient Gu was introduced to determine the evolution of grain size inhomogeneity during DRX. This coefficient accurately and objectively reflects grain inhomogeneity. The impact of the initial and recrystallized grain size on the inhomogeneity during DRX was also analyzed.