Effect of Deoxidation Sequence on Inclusions in Oriented Silicon Steel

In this study, industrial experiments and thermodynamic calculations were performed to compare the effects of different deoxidation methods on inclusions. The thermodynamic equilibrium between slag and liquid oriented silicon steel was studied at 1873 K (1600°C) to understand the influence of slag composition on oxygen content and the ability to absorb Al2O3. Thermodynamic calculations showed that the refining slag (w(CaO)/w(SiO2) = 2.54, w(CaO)/w(Al2O3) = 2.51) under the process of adding Fe-Si alloys first and then Fe-Al alloys during the tapping process had a stronger adsorption capacity for aluminum inclusions than that of the process of adding Fe-Al alloys first and then Fe-Si alloys, and resulted in a higher of molten steel cleanliness and fewer inclusions. A mathematical model was established to describe and predict the adsorption and removal of oxidized inclusions by slag through the study of slag viscosity and interfacial tension between slag and inclusions. The critical size of oxide inclusions in refining slag was calculated under different deoxidation methods.