A mean field model of dynamic and post-dynamic recrystallization predicting kinetics, grain size and flow stress
Résumé
A physically-based two-site mean field model has been developed to describe the microstructural evolution due to recrystallization during and after deformation. The model has been applied to predict the recrystallized fraction, recrystallized grain size, and flow stress of 304L austenitic stainless steel during discontinuous dynamic recrystallization (DDRX), post-dynamic recrystallization (PDRX) and grain growth (GG). The model parameters vary with temperature and strain rate but do not depend on grain size. In PDRX and GG regime, the parameters only depend on temperature. The model responds well to conditions with different temperatures, strain rates, strains and/or annealing times. Particular attention is paid to the occurrence of two-stage growth in the recrystallized grain size plots when PDRX occurs. There is a good quantitative agreement between model predictions and experimental results obtained in the different recrystallization regimes, opening the possibility of modeling multi-pass operations compatible with industrial applications.