Simulation of transient-state recrystallization of Al-4.5Mg-1Zn alloy after hot deformation

In this paper, a modeling framework developed for the simulation of recrystallization after hot deformation is presented. Modeling work concerned the recrystallization of an Al-Zn-Mg alloy in the transient state during post-deformation annealing when the stored energy and subgrain size were changing. The initial stored energy as a result of deformation was calculated as a function of subgrain size related to the Zener Hollomon parameter and its evolution was correlated with subgrain growth. The as-deformed grain structure was mapped into the Monte Carlo simulation. The calculated stored energy was assigned to the mapped structure, taking the length scale of the simulation into consideration. The effects of the Zener drag pressure and the initial as-deformed grain structure of the material on recrystallization were also incorporated into the Monte Carlo growth model. Static recrystallization (SRX) through the mechanisms of grain boundary (GB) and particle-stimulated nucleation (PSN) were distinguished. The parameters used for correlating the Monte Carlo simulation time with real time were determined by fitting the simulation results to the experimental measurements. The predictions from the simulations were validated by comparing the predicated grain structures with those from experimental observations. It was found that by incorporating the evolution of the stored energy into the recrystallization model, the differences between the simulation and experimental results could be reduced from 15% to 3%.