PROBLEM TO BE SOLVED: To prevent the variation of molten metal surface in a mold developed at the initial stage of casting having high hot strength and to enable the starting of stable casting by holding secondary cooling water temp. to the bottom part of a cast slab at the initial stage of the casting at a specific value. ;SOLUTION: The cast slab 4 drawn from the mold 1 with a dummy bar 3 is bent at the B end where roll group 2 is arranged curvedly and drawn. The cast slab 4 drawn from the mold 1 is cooled immediately with the secondary cooling water but at this time, in the case of the steel having high hot strength, the cast slab 4 at the bottom part is hardened and made to be difficult to be bent, therefore, the roll group 2 and the cast slab 4 are mutually and strongly interfered to cause what is called stepping phenomenon and the drawing speed of the cast slab is varied. In such a case, the strength of the cast slab is sufficiently lowered by holding the secondary cooling water temp. at ≥35°C, and since the cast slab is sufficiently and easily bent at the bending part and straightening part, the stepped part is not developed.;COPYRIGHT: (C)1999,JPO
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