METHOD FOR REFINING LOW NITROGEN AND LOW PHOSPHORUS MOLTEN STEEL IN CONVERTER

摘要

PURPOSE: A method for stable-refining of low nitrogen and low phosphorus molten steel in converter is provided. CONSTITUTION: In a manufacture method of low nitrogen and low phosphorus molten steel by converter refining process using hot metal and scrap as main raw materials, the present invention is characterized in that during the converter refining process, sinter ore is poured into molten steel in an amount of 3-5kg/ton·molten steel from 5 to 15% stage of blowing operation; sinter ore is again poured into molten steel in an amount of 3-5kg/ton·molten steel from 80 to 85% stage of blowing operation. In this method, furnace pressure is kept higher than atmospheric pressure at final stage of blowing operation. After above blowing operations, the molten steel has carbon content of 0.04-0.10 wt%, phosphorus content less than 0.02 wt% and nitrogen content less than 15ppm.