NUMERICAL SIMULATION ON SOLIDIFICATION MICROSTRUCTURE OF CAST STEEL USING CELLULAR AUTOMATON METHOD

The microstructure evolution of ASTM A216 WCA cast steel during solidification and consequent cooling process was simulated using a cellular automaton (CA) model. In the simulation, the growth velocities of delta/L and gamma/L interfaces were calculated based on the relationship between solid fraction and temperature predicted using Scheil model, and the growth velocities of gamma/delta and alpha/gamma interfaces were calculated using a mixed-mode model for multi-component systems. The peritectic solidification, alpha phase precipitation, and eutectoid transformation were simulated, and the grain size and area fraction of a phase as well as the mean interlamellar spacing of pearlite were obtained. To validate the model, a sand mold step-shaped casting was produced and metallographic examination was carried out. It was shown that the simulated results are in good agreement with the experimental results.