| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method for inexpensively and stably producing a clean cast slab of high quality whose surface layer part has reduced defects caused by nonmetallic inclusions without impairing productivity. SOLUTION: In the continuous casting method for an extra-low carbon steel cast slab containing≤0.003 mass% C, casting is performed while controlling so that in the case the total of 99,958×[mass%Sb], 386,147×[mass%S] and 853,354×[mass%O] exceeds 4,000 with respect to molten metal components, the flow velocity of the molten steel at the front face in the solidified shell of the slab in the vicinity separated by 100 mm from the molten metal surface of the molten steel in the mold to the downstream in the casting direction lies within the range of inequality; V≥-22.3/(99,958×[Sb]+386,147×[S]+853,354×[O]-4,000)+0.18 before casting; wherein V is the flow velocity (m/s) of the molten steel at the front face of the solidified shell; [Sb] is the concentration (mass%) of Sb in the molten steel; [S] is the concentration (mass%) of S in the molten steel; and [O] is the concentration (mass%) of O (dissolved oxygen) in the molten steel. COPYRIGHT: (C)2011,JPO&INPIT |
