| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the reoxidation of molten steel with slag and to adjust the slag component composition to the excellent Al2 O3 absorbing capacity by restraining oxygen potential in the slag in a ladle to low during interval from after tapping from a refining furnace to starting of casting. SOLUTION: Lime is charged at the time of tapping the molten steel from a converter and flux containing metallic Al is added into the ladle slag after tapping the molten steel, so that 0.8-1.4 (CaO)/(Al2 O3 ) in the slag by wt.%, 2-15 wt.% SiO2 and <=3.0 wt.% T.Fe are satisfied. Successively, an RH degassing treatment is executed, and during the treatment and/or after the treatment, lime or aluminum is added into the slag to keep the condition: 0.4-0.7 (CaO)/(Al2 O3 ), 2-15 wt.% SiO2 and <=3.0 wt.% T.Fe. An extra clean molten steel having extremely little Al2 O3 inclusion, can be produced.</p> |
