| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing continuously cast slabs, which method can expand an optimum casting condition by improving the efficiency of light rolling reduction in continuously casting molten steel while applying the light rolling reduction to the cast slabs, and can manufacture the cast slabs having the small central segregation and being capable of satisfying the recent severe quality requirement. SOLUTION: When the continuously cast slabs are manufactured, the rolling reduction of the cast slabs 12 is started from the position where the solid phase rate at the central portion of the thickness of the cast slabs 12 is lower than 0.4, and is continued until the position where the solid phase rate at least at the central portion of the thickness of the cast slabs 12 becomes higher than 0.7. In this case, the surface temperature at the middle portion of the long side of the cross section of the cast slabs is kept to be higher than 750°C until the position where the solid phase ratio at the middle portion of the thickness of the cast slabs becomes at least 0.5, and the surface temperature at the middle portion of the long side of the cross section of the cast slabs is kept to be lower than 850°C at the position where the solid phase ratio at the middle portion of the thickness of the cast slabs is higher than 0.5, and the rolling reduction is continued. Thus, the cast slabs having the small central segregation can be manufactured. COPYRIGHT: (C)2008,JPO&INPIT
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