반응 모델을 활용한 2차 정련 간 개재물의 변화에 대한 속도론적 해석

Abstract

For production of high-end grade steel, the behavior control of non-metallic inclusion is highly important issue. Especially, MgO·Al2O3 spinel inclusion diminishes the steel properties due to a higher melting point and lower deformation. Moreover, it has higher adhesive tendency to nozzle materials, the spinel inclusion is able to influence on nozzle clogging during the process. Therefore, the spinel inclusion is necessary to be controlled during the ladle treatment, Many previous researchers reported the generation mechanism of spinel inclusion during ladle treatment. They discovered, Al2O3 inclusion was formed by Al-deoxidation, and Al2O3 inclusion evolves to MgO·Al2O3 spinel inclusion with increasing Mg content in the molten steel. Its Mg content was supplied by the reduction of the slag and the dissolution of the MgO-based refractory. However, the complex reactions occur simultaneously among molten steel, slag, inclusions, refractory and the alloying additions during the ladle treatment. Therefore, it is not simple to predict the behavior control of inclusions during ladle process. In order to suppress and control the spinel generation, the kinetic model is necessary to predict the compositions and amounts of the molten steel, slag and inclusions in the ladle treatment. In this study, the kinetic model based on the coupled reaction model was used to investigate the compositions and amount changes among the molten steel, slag and inclusions during the ladle treatment. The influence on the spinel generation with changing the slag compositions was investigated using a simulation model.