A dynamic model of alumina inclusion collision growth in the continuous caster

Abstract

The number and morphology of non-metallic inclusions are the key factors to estimate the quality of the steel product, so it is of particular importance to have a profound knowledge about the collision and aggregation among the inclusions in the molten steel. In this paper, a three-dimensional mathematic model was developed to predict the dynamic growth of alumina inclusions in the continuous caster. This model includes Eulerian approach for turbulent flow field and inclusion’s concentration and number density fields, and Lagrangian approach for inclusion’s collision growth. The numerical results indicate that the convective transfer leads to the ‘W’ distributions of inclusion in the continuous caster. This phenomenon is consistent with Javurek’s experiment. For a single inclusion, the larger inclusion has more chances to trap other inclusions, and the trapped inclusions tend to be the smaller inclusions with diameter less than 10μm. The aggregated inclusions are dendritic with some tips and arms, which have been observed in Yin’s experiment. Cluster formation of alumina inclusion depends on the turbulent flow, which contributes to the enhancement of the collision rate and determines the inclusion growth mechanism.