| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method for steel which enables manufacturing of a cast slab having little center segregation through both the entire length and the entire width of the cast slab. SOLUTION: In a method to apply reduction after bulging on a rectangular cast slab of 150-370 mm thick, the reduction is applied with 2 pairs or more of reduction rolls at a reduction gradient of 1.5-5 mm/m in a first reduction stage where a reduction area covers from the highest upstream of a reduction area in a second reduction stage to a maximum of 6 m to the upstream side. In the second reduction stage, whose reduction area corresponds to a solid phase rate fs in the center of thickness of 0.20-0.95, the reduction is applied with a pair or two pairs or more of reduction rolls, with each rolling reduction amount of more than 15 mm and the reduction gradient of 40 mm/m or more. The total amount of rolling reduction in the first and second reduction stages is less than a thickness equivalent to the bulging.
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