| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing high-cleanliness steel, which sufficiently reduces an amount of non-metallic inclusions to manufacture the high-cleanliness steel. SOLUTION: The method for manufacturing the high-cleanliness steel by the steps of ladle-refining a molten steel tapped out from a converter, and vacuum degassing and refining the molten steel with the use of a reflux-type vacuum degassing apparatus includes: refining the molten steel so that the component value of Al after the molten steel has been ladle-refined can be 0.030% to 0.070%; optimizing FeO, MnO, CaO, SiO<SB>2</SB>, MgO, Al<SB>2</SB>O<SB>3</SB>and TiO<SB>2</SB>, which are the composition of slag after the ladle refining step; and also optimizing a stirring period of time and an amount of molten steel to be refluxed, in the vacuum degassing and refining step. COPYRIGHT: (C)2009,JPO&INPIT
|
