Numerical Modeling of a Reactive Liquid–Solid Phase Transformation in Molten Steel

A numerical framework is developed to simulate reactive liquid–solid phase transformations in molten steel by coupling chemical reactions, phase-field evolution, and solute diffusion, together with thermodynamic data for oxide formation. The growth of spherical inclusions is governed by the coupling effects of reaction kinetics, thermodynamic driving force, and interfacial properties, exhibiting a non-monotonic temperature dependence. Simulations of the co-evolution of Al2O3 and SiO2 inclusions further show that the morphology of duplex inclusions is essentially controlled by the balance between oxide-solute supply and transformation kinetics. The introduction of interfacial energy anisotropy reproduces dendritic morphologies, revealing that oxide-solute supply, interfacial anisotropy, and interfacial instability together control directional growth and branching behavior. The proposed framework provides a general approach for modeling reactive multiphase transformations.