METHOD FOR SMELTING HIGH-CLEANLINESS STEEL

摘要

PROBLEM TO BE SOLVED: To exceedingly improve the cleanliness of molten steel by making the immersion depth of an immersion tank into the molten steel shallow before adding alloys for component adjustment to the molten steel at the time of adjusting the molten steel components by adding the alloys for deoxidation and component adjustment into the molten steel in a ladle in the state of immersing the lower part of the immersion tank into the molten steel. SOLUTION: The molten steel 2 where slag 3 floats on the front surface is housed into the molten steel ladle 1 and the lower part of the immersion tank 4 as an immersion type simple refining device is immersed into the molten steel 2. The alloys 13 for deoxidation and component adjustment and boundary shielding materials 5 are added into the immersion tank 4 from above and a stirring gas is supplied to the molten steel 2 from a gas blowing plug 7 disposed at the bottom of the molten steel ladle 1 to fluidize the slag metal boundary. At this time, the immersion depth of the immersion tank 4 into the molten steel 2 is made shallow before the addition of the alloys 13 for component adjustment to direct the main flow of the molten steel flow toward the slag-metal boundary direction. Conversely the alloys 13 for deoxidation and component adjustment or their components are made to ride on the flow of the molten steel 2 subjected to thickening by utilizing the fluidization of the slag-metal boundary.