Finite element analysis of ferrite–austenite diffusion controlled phase transformation

The ferrite–austenite transformation, that takes place in stainless steel manufacture, is studied as a numerical experiment. The diffusion process of Cr, Ni and Fe between ferrite and austenite is modeled as a mass transfer problem with a moving boundary. Equilibrium is assumed at the interface between the two phases. The resulting system of governing equations is solved simultaneously with the Galerkin finite element method. The model is validated against analytical solutions and extensive experimental data for ferrite and austenite size and composition versus time. It is believed that the present approach may be applied in the modeling of other phase transformations that exhibit similar diffusion and equilibrium phenomena.