Micro-scale Cellular Automaton Modeling of Interface Evolution During Reaustenitization from Pearlite Structure in Steels

A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations of both the austenite–ferrite and austenite–cementite interfaces coupled with the carbon diffusion and redistribution are integrated. The capillarity effect derived from local interface curvatures is also carefully considered by involving the concentration given by the phase diagram modified by the Gibbs–Thomson effect. This allows the interface evolution from a transient state to a steady state under different annealing conditions and various interlamellar spacings to be simulated. The proposed cellular automaton approach could be readily used to describe the kinetics of austenite formation from the lamellar pearlites and virtually reveal the kinematics of the moving interfaces from the microstructural aspect.