Fe-C peritectic solidification of polycrystalline ferrite by phase-field method

Abstract A multi-phase-field model was applied to simulate the polycrystalline solidification of δ phase (δ-ferrite) and peritectic solidification of γ phase (γ-austenite) in Fe-C system. Four main modes of phase transformation are included in this simulation, which are solidification of δ phase L → δ, solidification of γ phase L → γ, peritectic transformation δ → γ and peritectic reaction L + δ → γ. The results reveal that the redistribution and diffusion of carbon not only controls the movement of δ-liquid, γ-liquid and γ-δ interfaces but also lead to the production of liquid channels and melting pools. In addition, the evolution of the volume fractions of each phase was analyzed, which shows the statistical law of the interaction of δ, γ and liquid phases at different stages. The present study therefore contributes to the understanding of polycrystalline simulation of Fe-C peritectic solidification and clarifies the formation mechanism of microstructure and micro-segregation.