Modeling the dynamic recrystallization under multi-stage hot deformation

The kinetics of the restoration processes that take place during the isothermal annealing of metals for the case when the critical strain for the onset of dynamic recrystallization is reached and exceeded were modeled using the Cellular Automata approach. The model enables both quantitative and topographic simulations of microstructural evolution before and during metadynamic recrystallization. It allows the simulation of multi-stage deformation. It was observed that two kinds of transition between the strain-dependent and strain-independent range are possible: the first is smooth, whereas the second is oscillatory. The post-dynamic softening is shown to be weakly dependent on strain and temperature, but strongly dependent on strain rate, as has been observed in published experimental work. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.