Thermodynamic analysis of steel deoxidization processes during tapping and refining operations

A thermodynamic model based on the interaction parameter approach for molten metal solutions and a quasi-chemical model for molten slags and non-metallic inclusions was employed to analyze steel deoxidation during tapping and refining operations in a ladle furnace. This model is able to predict the mineralogical nature of non-metallic inclusions and their amount through thermodynamics and mass balances. It was found that the addition sequence of deoxidizers during a tapping procedure influences the nature and amount of the different inclusions. Besides, the metal-slag equilibrium is readily reached after tapping and at the end of steel treatment in the ladle furnace. The model proved to be useful for steel cleanliness assessments and the design of steel deoxidization practices.