Barium as deoxidant and modifier of liquid steel

Thermodynamic functions of reactions of deoxidation by barium of liquid steel are analyzed. Solubility surfaces for conditions of deoxidation of liquid steel by barium alloys with silicon and aluminium are drawn. It is shown that the description of regularities of deoxidation by barium is really possible only if the constant of deoxidation by barium is about 10 -4-10 -5. Owing to small solubility and great molecular weight barium cannot be an effective deoxidant. From recommendations available in literature about the selection of modifiers and surface properties of barium in metal it is shown that the barium entered into steel at the final stage of refinement is capable to reduce the amount of nonmetallic inclusions and to refine the primary grain of cast metal. The conclusion is drawn that barium is not an effective deoxidant but can play the role of a modifier.