Flow Dynamics and Inclusion Transport in

The quality of continuous cast steel depends greatly on the extent of inclusion particle entrapment, which is governed by flow transport phenomena in the mold region. As part of a long-term effort to develop and apply comprehensive models of these and other phenomena, this paper reports on work during the second year of this NSF grant that aims to develop quantitative models of transient flow of molten steel, superheat and inclusions during the continuous casting of steel, and to apply them to improve understanding and efficiency of inclusion particle removal in the process. Results are reported here for five interrelated subprojects. Firstly, models of transient flow using Large Eddy Simulation (LES), which were previously validated and used to predict flow, are used here to predict the accompanying transport of inclusion particles. Of most significance, the model can predict the ultimate distribution of inclusions in the final product. Models are then applied to investigate the effect of nozzle geometry on flow and inclusion removal. Thirdly, model improvements are presented to predict inclusion size distribution evolution. As inclusion removal in the mold is shown to be quite small, simulations are extending upstream to investigate inclusion removal during ladle refining. Fourthly, behavior of the top surface flux layers, which is important to inclusion removal, is computed, including the effects of natural convection. Finally, accurate simulation of superheat transport in the molten pool due to jet impingement is demonstrated.