| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for inexpensively and atably producing a clean and high-quality slab which is less in defects caused by nonmetallic inclusions such as alumina clusters on the surface layer part of the slab. SOLUTION: In the method for continuously producing an extra-low carbon steel slab comprising ≤0.003 mass%, in the case the total of 24,989×[mass%Ti], 386,147×[mass%S], 8,533,530×[mass%O] and 118,173×[mass%Sb] exceeds 4,000, casting is performed so as to be controlled in such a manner that the flow velocity of a molten steel in the front face of the solidified shell of the slab lies within the range of inequality (1): (0.4-2.2V)×(6.7×[T.O])≤1/(24,989×[Ti]+386,147×[S]+8,533,530×[O]+118,173×[Sb]-4,000).. (1), wherein: V denotes the flow velocity of the molten metal in the front face of the solidified shell; [T.O] denotes the total oxygen concentration in the molten steel; [Ti], [S], [O] and [Sb] denote the concentration of Ti, the concentration of S, the concentration of dissolved oxygen and the concentration of Sb in the molten steel, respectively. COPYRIGHT: (C)2010,JPO&INPIT
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