Steel melting and secondary-refining method

摘要

A steel melting and secondary-refining method comprising the steps of: melting steel manufacture raw materials while the molten steel is subjected to oxidation and decarburization so that the oxidation and decarburization are substantially completed before melt-down; after melt-down, heating the molten steel to a temperature above a liquidus line temperature and below 50 DEG C. in temperature increment from the liquidus line temperature, and thereafter tapping the molten steel into a primary ladle; teeming the molten steel from the primary ladle into a secondary refining furnace; allowing the molten steel to be effluent into a secondary ladle at a lower portion of the secondary refining furnace while the temperature of the molten steel is raised; and continuously performing gas bubbling in the secondary ladle in a vacuum under existence of slag simultaneously with the effluence of the molten steel into the secondary ladle.