Motion behaviour of solid inclusions at the steel–slag interface in high-Al steel

Abstract

In the steelmaking process of high-Al steel, solid inclusions will accumulate in the slag phase near the steel–slag interface, and it is crucial to eliminate the residual Al-containing inclusions in molten steel. In the present study, the film-rupture and drainage models were applied to clarify the characteristics of the inclusion detachment motion. The analysis of parameters was carried out and their impact on the inclusion motion was further discussed. It was found that the micro-size inclusions are prone to remain at the interface or rebound back into the steel. According to the models, the motion of the solid inclusion in the drainage stage is solely influenced by the steel density and the interfacial tension between steel and slag. The decrease of the steel–slag interfacial tension is beneficial to the transfer of the inclusions, while the low-density of the high-Al steel will promote the rebound of the inclusions.