| 摘要 |
PROBLEM TO BE SOLVED: To provide a secondary refining method for molten steel which, in a secondary refining process for the molten steel with a CAS method, enables a blow of an inert gas into the molten steel without installing a porous plug on the bottom of a ladle, and enables temperature rise of the molten steel by CAS-OB; a secondary refining apparatus for the molten steel; and the lance used therein for secondary refining. SOLUTION: The secondary refining method of blowing the inert gas into the molten steel in the ladle comprises blowing the inert gas into the molten steel from the gas-blowing lance 5 immersed in the molten steel, and blowing oxygen gas from an oxygen-blowing nozzle 7 arranged at the halfway of the gas-blowing lance 5, onto the surface of the molten steel in the space 24 surrounded by the dip tube 4 that is arranged at such a position as to surround the region on the molten steel surface, to which the inert gas moves up, and that immerses its lower part in the molten steel surface. COPYRIGHT: (C)2005,JPO&NCIPI
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