A Mixing Model Using Scale Factors for Prediction of Intermixed Bloom Concentration of 0.4mass%C-0.2mass%Si-0.7mass%Mn Steel in Continuous Casting

Abstract

Although there have been studies on models for predicting the mixing concentration of elements between old and new molten steel with different chemical components during continuous casting, there is limited information about the concentration of the mixed portion in the cross-sectional and the longitudinal directions of the intermixed bloom. In the present study, the concentration of the intermixed bloom generated by the different-grade continuous casting is measured in the cross-sectional and the longitudinal directions. A significant difference in the concentration of the mixed portion is noticed at different heights along the thickness direction of the intermixed bloom. Based on the measurement results, we propose a new mixing prediction model that can accurately predict the concentration of the mixed portion at the subsurface and the center in the intermixed bloom along the longitudinal direction. The present results show that each height which has the minimum and the maximum concentrations of the mixed portion in the crosssection varies along the longitudinal direction of the intermixed bloom. This implies that the maximum and the minimum concentrations of the mixed portion in the cross-section do not necessarily occur only at the surface and the center of the intermixed bloom. The newly proposed mixing prediction model can be employed to cut off the mixed portion by predicting the minimum and maximum concentrations of the mixed portion in the cross-section along the length direction of the intermixed bloom. © 2023 The Iron and Steel Institute of Japan.