Prediction on the Composition Distribution of Oxide Inclusions in a Tire Cord Steel Billet Using an Integrated Model

An integrated model was proposed in the current study to predict the composition distribution of inclusions along the thickness of a tire cord steel continuous casting billet. The thermodynamics, kinetics, fluid flow, heat transfer, solidification, and element segregation were combined in the integrated model. More accurate results were obtained using the current model compared with the published work, indicating the great importance of the kinetics and element segregation in the inclusion predication. Thermodynamic calculation showed the equilibrium composition of inclusions at 1073 K was approximately 92 wt pct SiO 2 –3 wt pct MnO–4 wt pct Al 2 O 3 –1 wt pct CaO, which was obviously different from measured results, even though the element segregation was premeditated, indicating the insufficiency of the thermodynamics in predicting the inclusions composition in the billet. A large positive segregation of C, Si, Mn, and S at the center of the billet was revealed, and the average segregation index was simulated to be 1.89, 1.05, 1.08, and 1.26, respectively. The strong element segregation of the steel induced a fluctuation in the composition of inclusions along billet thickness, which was more accurate compared with the model ignoring the element segregation.