A Practical Model for Predicting Intermixed Zone During Grade Transition

Abstract

This article proposes a new mixing model for predicting the composition distribution in continuously cast steel during a grade transition. The transient model consists of two sub-models, one for mixing in the tundish and the other for mixing in the liquid pool of the strand. The Cho and Kim's simple tundish mixing model (which is very efficient and practical) is adopted as the present tundish model. For the mixing model in the strand, the concept of Cho and Kim's tundish model was extended to the strand. In order to verify the proposed model, plant tests were conducted on three kinds of casters (slab, bloom and thin slab caster) during the grade transition period of continuous casting under various conditions. The real grade intermixed slabs and blooms were produced and the composition distributions were measured and compared. When the proposed model was applied to several cases of the slab, bloom and thin slab casting, the numerical results were found to be in good agreement of the experimental data. These findings verify that the proposed model is capable of tracking mixing phenomena for arbitrary casters and operating conditions.