Modelling post-deformation softening kinetics of 304 austenitic stainless steel using cellular automata

The softening mechanisms after hot deformation of an austenitic stainless steel under different thermomechanical conditions were modelled using a 2D cellular automaton (CA) model. The input data to the CA model included stored energy during deformation, different levels of dynamically recrystallized (DRX) microstructures, temperature, strain and strain rate. The effects of the parameters were studied on the static and meta-dynamic recrystallization (SRX and MDRX, respectively) kinetics using the CA model. As in reality, it is not possible to abandon DRX episode from the experimental procedure and obtain SRX or MDRX, it would not be practical to study the effect of DRX on the consequent SRX and MDRX. To study the explicit effect of DRX on the post-deformation softening kinetics, deformation was simulated with and without the occurrence of DRX. Comparison of the results for the two different deformation conditions revealed that DRX and the partial recrystallized austenitic microstructure affected the post-deformation softening mechanisms by a deceleration of the post-deformation recrystallization kinetics and that the time for 50% recrystallization (t50) decreased with increasing strain, strain rate and temperature for a given initial grain size.