Effect of Changes in Sulfur and Oxygen Concentration on Change in Nitrogen Concentration in Liquid Steel during CaO–CaSi Powder Blowing under Reduced Pressure

Abstract

In this paper, 1500 kg scale experiments of CaSi mixed CaO powder top blowing onto the Al killed steel were carried out under reduced pressure. And the effects of CaSi alloy ratio in the mixture on reactions of desulfurization and nitrogen removal were examined. Aluminum decreasing rate decreased and rate constant of desulfurization and nitrogen removal increased with increasing CaSi mixing ratio to flux. It is supposed from the above that deoxidation and desulfurization reaction can simultaneously occur by blowing the mixture of CaSi and CaO powder and the effect of calcium mixing powder on desulfurization can be explained by promotion of CaO desulfurization and CaS formation. It is suggested that lower oxygen and sulfur activity due to reaction between molten steel and powder with CaSi increased rate constant of nitrogen removal.