In-Situ Observation of the Modification Behavior of Alumina Inclusions in a Calcium-treated Steel

Abstract

In the current study, a novel laboratory experiment and a kinetic calculation were proposed to analyze the modification behavior of alumina inclusions in the molten steel. To obtain the shape and composition of a single Al2O3 inclusion at different times during the modification process, confocal scanning laser microscopy experiments were conducted to track the evolution of the Al2O3 inclusion particle on the surface of Ca-treated steel. Then, the composition evolution of the Al2O3 inclusion particle during the modification process was predicted using a kinetic model. It was assumed the product layer was homogeneous. The diffusion of dissolved [Ca], [Al], and [O] crosses through the inclusion-steel interface was considered. Experimental results agreed well with kinetic calculated results. Meanwhile, the kinetic model was used to analyze the modification behavior of Al2O3 inclusions in steel with various influence factors including the [Ca] content in steel, the [Al] content in steel, and the initial size of inclusions.