REFINING METHOD OF Ni-RICH MOLTEN STEEL CONTAINING 30 TO 50 OF Ni

摘要

PURPOSE: A refining method of molten steel is provided which manufactures molten steel containing high Ni content and having high purity without pickup of carbon and improves productivity by shortening process time. CONSTITUTION: The refining method of molten steel comprises first step of decarburizing and desulfurizing the molten steel by transferring molten steel containing 30 to 50 wt.% of Ni to an argon oxygen decarburization (AOD) refining furnace; second step of removing slag from the molten steel after transferring the molten steel from the AOD refining furnace to a ladle; third step of dephosphorizing and dechromizing the molten steel by transferring the molten steel from the ladle to the AOD refining furnace again; and fourth step of deoxidizing the molten steel by transferring the molten steel from the AOD refining furnace to a vacuum oxygen decarburization (VOD) refining furnace.