METHOD FOR PROMOTING DESULFURIZATION OF MOLTEN STEEL BY CaO-CaCN2 MIXED COMPOSITION

摘要

PURPOSE: A method for promoting desulfurization of molten steel by injecting a mixed composition containing CaO-CaCN2 into a naked molten metal forming part of molten steel when vacuum refining molten steel in RH tank in the steelmaking refining process is provided. CONSTITUTION: In a method for promoting desulfurization of molten steel in RH tank when manufacturing steel containing 0.05 wt.% of carbon (C), 0.1 wt.% of manganese (Mn), 0.012 wt.% of phosphorus (P), 0.012 wt.% or less of sulfur (S) and a balance of Fe and other impurities, the method comprises a step of injecting a mixture of CaO and CaCN2 into a naked molten metal forming part of the molten steel; a step of fixing sulfur contained in the molten steel as CaS using the mixture of CaO and CaCN2; and a step of removing the CaS as slag, wherein content of CaO is 80 wt.% or less in the step of injecting a mixture of CaO and CaCN2 into a naked molten metal forming part of the molten steel.