In-situ analysis and numerical study of inclusion distribution in a vertical-bending caster

Abstract

Based on a fast-detection platform (FDP) founded by us, an in-situ measurement of inclusion distribution in slab is successfully performed. The inclusion distribution is obviously asymmetry and non-uniform. Specially, due to the structure differences in the vertical and bending part of a slab caster, the inclusion distribution in these two parts are quite different: In the vertical part, the inclusions entrapped in the outer arc is much more than that in the inner arc, while in the bending part, the inclusions entrapped in the outer arc is a little less than that in the inner arc. Large inclusions are tend to be found near the surface, and sometimes in the center, but they’re very few. Then in order to interpret the inclusion distribution in practical measurements, a new LES model is established using Euler-Lagrange approach. A new entrapment criterion is also defined to calculate the entrapped inclusions. Big inclusions are tend to float up to the mold top, and aggregate near the outer arc, which can explain the differences of inclusion distribution in the vertical part; Smaller inclusions are easier to flow deep into the mold, and become clusters when they’re getting near, which can explain the big inclusions in the central part. What’s more, the drag effect of bending slab is proven to be responsible for the differences of inclusion distribution in the bending part. This mathematical model is helpful for understanding the inclusion movements in slab.