Modeling of reaustenitization of hypoeutectoid steels with cellular automaton method

A model for simulating reaustenitization of hypoeutectoid Fe-C steel has been developed using a cellular automaton approach (CA). The prior microstructure state for quenching can be predicted through grain size, fraction of austenite, and distribution of carbon concentration. The kinetics of austenitization are simulated by simultaneously considering continuous nucleation, grain growth and grain coarsening. In the current CA model, carbon distribution in ferrite (α), austenite (γ) and α/γ interface is calculated without identifying the state of each cell. The competition between the nucleation and early stage grain growth in the pearlite is revealed, and the simultaneous phase transformation from ferrite to austenite and the austenitic grain coarsening in the austenitic region are also shown. A simple approach is proposed to eliminate the artificial anisotropy problem in representing microstructure evolution in CA method. The simulated results are in good agreement with the available experimental data.