Deoxidation and Inclusion Control for Alloy Steel

Abstract

DEOXIDATION of quality steels is directed toward the casting of sound ingots free from excessive segregation, having good rolling and forging characteristics, and containing it minimum of harmful impurity elements and inclusions. In addition, deoxidation is employed for grain size control to promote maximum toughness of the steel. These objectives are a chieved by selection of suitable charge material, slag control and initial deoxi-dation practice in the furnace, and final deoxidation practice in the ladle. Although much has been learned of the physical chemistry of the process,the art of steel-making is still in large part empirical, and successful practices are somewhat difficult to rationalize. For this reason, equilibrium relations in the iron-oxygen deoxidizer systems are important, but the kinetics of deoxidation and the sequence of operations may be more significant to the operator.