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.

中文翻译：

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多晶铁素体Fe-C包晶凝固相场法

摘要 应用多相场模型模拟Fe-C系中δ相（δ-铁素体）的多晶凝固和γ相（γ-奥氏体）的包晶凝固。该模拟包括四种主要的相变模式，即δ相L→δ凝固、γ相L→γ凝固、包晶相变δ→γ和包晶反应L+δ→γ。结果表明，碳的重新分布和扩散不仅控制了δ-液体、γ-液体和γ-δ界面的运动，而且导致了液体通道和熔池的产生。此外，还分析了各相体积分数的演变规律，揭示了不同阶段δ、γ和液相相互作用的统计规律。