Modeling on the Composition Spatial Distribution of Inclusions in Steel Continuous-Casting Blooms with Considering Element Segregation

Abstract

One of the most important key technologies to ensure a good-quality continuous-casting bloom is the accurate identification, prediction, and control of the composition of inclusions. In the current article, a comprehensive numerical model is established by integrating fluid flow, solidification, mass and heat transfer, and inclusion-related thermodynamics and kinetics to predict the evolution of Al₂O₃, CaO, SiO₂, CaS, and MgO of inclusions depending on the location on the cross section and the length of the steel continuous-casting bloom. A key innovation of this study lies in the incorporation of element segregation into the kinetic calculation of inclusion composition: instead of assuming constant element content during solidification, the model dynamically computes inclusion evolution based on the spatial variation of elemental concentrations within the bloom. To validate the simulation, field emission scanning electron microscopy is employed to characterize inclusion distributions experimentally, showing good agreement with the model predictions. Both the calculation results and the measure results indicate the highest Al₂O₃ mass fraction at the bloom center and a decreasing tendency toward the edge and an enriched accumulation of CaO approximately one-quarter of the bloom cross section with CaS content appearing diluted in locations rich in CaO.