| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for producing a clean steel, such as a bearing steel having≤0.0030% Ti and≤0.0010% T.O by using a ladle-refining facility having pressure-reducing function while using flux containing no fluorine as the refining agent. <P>SOLUTION: After tapping off the molten steel from a converter or an electric furnace, the molten steel and slag are stirred and refined by using Ar or N<SB>2</SB>gas under reducing pressure in the ladle, and the flux containing the fluorine, is not used as refining agent, and the slag composition after ladle-refining, is made, by mass, to be≤1.0% TiO<SB>2</SB>and 0.05-1.00% as the total of Na<SB>2</SB>O and K<SB>2</SB>O under condition of 30-60% CaO, 3.0-15% MgO, 10-30% Al<SB>2</SB>O<SB>3</SB>and 2.0-10.0 (%CaO/%SiO<SB>2</SB>). <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
