Martensitic microstructure evolution in austenitic steel: A thermomechanical polycrystalline phase field study

Abstract

We have performed coupled thermomechanical phase field simulations of martensitic transformation in single-crystalline and polycrystalline 301-stainless steel by coupling Ginzburg–Landau equation to the mechanical equilibrium and non-stationary heat conduction equations. Simulations accounted for elastic anisotropy, under different thermal and mechanical BCs, i.e., clamped, embedded, and near-open, as well as adiabatic and isothermal with and without latent heat effects. To the best of authors’ knowledge, no such simulations are reported in literature on polycrystalline materials which provides the effects of various thermomechanical BCs incorporating latent heat. We have utilized a multivariant single embryo as an initial condition in both systems to mitigate the lack of nucleation criteria at the mesoscale; without any initial constraint, the model can select the martensitic transformation path and final microstructure. Simulations showed excellent capabilities in predicting influence of such thermomechanical BCs on martensitic microstructural formation including autocatalytic transformation process in polycrystalline steel and its evolution. Martensitic microstructure in a single-crystalline, and b polycrystalline steel, in deformed configuration (deformation scale factor is $$1\times$$ ) for near-open, embedded, and clamped boundary conditions (from left to right). Dataset edges in blue show initial undeformed configuration