DESULFURIZATION REFINING METHOD OF MOLTEN STEEL

摘要

PURPOSE: To execute stable desulfurization refining with high reliability by blowing a desulfurizing flux which is mainly composed of CaO and CaF2 and is specified in grain size distribution into molten steel under specific conditions at the time of desulfurizing the molten steel by an RH desulfurization refining method. CONSTITUTION: The desulfurizing flux which consists of the compsn. consisting essentially of the CaO and CaF2 and is of >=70% in the volumetric compounding ratio of raw material particles having a grain size of <=75μm is used at the time of desulfurizing the molten steel by using a RH vacuum degassing equipment. The desulfurizing flux is blown into the steel bath in an RH degassing chamber or into the steel bath surface or toward the molten steel reflux rising from the lower part of a riser under the conditions under which the value of a flux blowing rate (kg/min)/molten steel circulating rate (ton/min) is <=3kg/ton. As the result, the desulfurizing flux is uniformly mixed into the molten steel to accelerate the desulfurization reaction.