Evaluation of Activity Coefficients of Oxygen and Nitrogen in Molten Alloy and Its Dominant Factors Based on Solvation Shell Model

Abstract

Activity coefficients of light elements in molten metals and alloys are important thermodynamic properties for refining and inclusion controls of metallic materials. Activity measurements of the activities of light elements in pure metals have been carried out by previous studies. Also activities in molten alloys have been previously investigated and summarized using interaction coefficients. However, it is still difficult to accurately explain the activities of light elements in molten alloys over a wide range of temperatures and concentrations. In this study, with the aim of unified understanding of the thermodynamic behavior and solubility of light elements in various molten alloys, we studied the activity coefficients of oxygen and nitrogen in molten alloys using solvation shell model, and examined the factors governing the activity coefficients of oxygen and nitrogen in molten alloys.