Reactivity of Selected Oxide Inclusions with CaO-Al2O3-SiO2-(MgO) Slags
Inclusion content minimization is key in the production high quality steels. This is typically achieved through approaches ranging from preventing inclusion formation via process control to optimising process conditions to remove any inclusions that form. Inclusion removal from steel is generally through reaction with a slag. The inclusion transfers across the steel-slag interface to dissolve in the slag. This transfer process is primarily a dynamic interfacial tension/wetting driven process. In this study, the dynamic wetting (θ) of a range of slags in the CaO-Al2O3-SiO2-(MgO) system on alumina (Al2O3), magnesia spinel (MgAl2O4) and calcium aluminate (CaO.Al2O3) substrates has been assessed using the sessile drop technique. The reactivity of selected inclusion phases was studied by evaluating the wetting results and characterizing the microstructure of the slag-inclusion interface. It was found the dependence of θ value on the composition was lower for the basic ladle type slags than the acid tundish type slags.