Chracterization of Recrystallization Microstructure of Steel Alloys by Multi Phase Field Model Assisted by Data Assimilation Technique.

Recrystallization is a fundamental phenomenon in steel metallurgy. Through recrystallization, we can complete the creation of the desired microstructure. The critical aspects of the microstructure are grain size distribution, grain orientation texture, and precipitated particles.<br/>The John-Mehl-Avrami equation can describe the kinetics: however, we can not yet make a quantitative prediction related to the recrystallization. In this study, we carry out the ICME approach combined with CPFEM and phase field approach. The CPFEM simulation prepares the initial state of recrystallization for cold-rolled steel sheets, and we implemented the phase field calculation with the data assimilation technique. Data assimilation is required to determine the phase field model parameters such as grain boundary energy and mobility. We validate the modelling results with the annealing experiments for various Fe-C alloys. With the framework, we can characterize the recrystallized microstructure. The characterization contains grain size distrubtion, orientation texture, and the effect of initial conditions, including plastic deformation and precipitates.