| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of stably reducing the dust producing quantity in a high carbon concentration region at the first half period of the refining, and also stably suppressing the chromium oxidizing quantity at the ending period of the refining when producing a chromium-based stainless steel by a decarbonization refining process. SOLUTION: When smelting the chromium-based stainless steel having 10 mass% to <25 mass% chromium concentration by applying the decarbonization refining while blowing oxygen from a top-blowing lance, at the first half of the refining, top-blowing oxygen flowing quantity is defined as the range of 140 Nm<SP>3</SP>/hr to <220 Nm<SP>3</SP>/hr per one ton of molten steel, and at the time when the decarbonization proceeds in the range of≤2% to≥0.5% carbon concentration, the top-blowing oxygen flowing quantity is reduced so as to become in the range of 75 Nm<SP>3</SP>/hr to <120 Nm<SP>3</SP>/hr per one ton of molten steel, and the distance LG between the top end of the lance and the standstill surface of the molten iron is adjusted so that the L/L<SB>0</SB>of molten iron recessed depth L to the top blowing oxygen jet and the molten iron depth L<SB>0</SB>is in the range of 0.2-0.5 through the refining. COPYRIGHT: (C)2009,JPO&INPIT
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