A fully coupled crystal plasticity-cellular automata model for predicting thermomechanical response with dynamic recrystallization in AISI 304LN stainless steel

A microstructure-based multiscale framework was developed to physically correlate the microstructure evolution and mechanical behavior of AISI 304LN stainless steel during the thermomechanical process. The developed model couples a crystal plasticity finite element method (CPFEM) to simulate heterogeneous deformation and a probabilistic cellular automata (CA) approach with a dynamic recrystallization (DRX) model to simulate microstructure evolution. Specifically, the CA model was built with formulations with physical meaning and combined with CPFEM by updating algorithms with higher robustness. The developed model was validated by comparing it with the experimental results of AISI 304LN stainless steel under thermo-mechanical processing at various temperatures and strain rates. The predicted flow stresses, grain sizes, DRX volume fraction, and deformed texture match well with the experimental data. Additionally, the developed model can simulate microstructure evolution by the DRX process, whereby the evolutions of recrystallized grains and pole figures can be examined. Moreover, the mechanical responses during the nucleation and growth of recrystallized grains can be characterized by in-depth quantitative analysis considering grain-level deformation inhomogeneity.