| 摘要 |
PROBLEM TO BE SOLVED: To prevent the defect of shrinkage cavities easy to be generated upon continuous casting for an alloy steel comprising ≥5 mass% Cr. SOLUTION: In the method for subjecting an alloy steel comprising ≥5 mass% Cr to continuous casting, a mold whose cross-sectional face is circular, or elliptical close to the circular one or oval is used, and mold flux having a crystallization temperature T<SB>C</SB>lower by 50 to 300°C to the liquidus temperature T<SB>L</SB>of the alloy steel fed to the mold is used. While cooling the surface of a slab under the conditions where secondary cooling ratio water quantity is 0.1 to 1.2 L/kg-steel, after the slab cast at a speed of ≥0.5 m/min is solidified to the central part, first rolling reduction of rolling down the slab using rolls in a continuous casting machine so as to obtain a flat slab is performed, and subsequently, till the performance of second rolling reduction circularly straightening the flat slab in such a manner that the cross-sectional face is made circular, secondary cooling of cooling the surface of the slab is not performed. The defect of shrinkage cavities in the central part of the slab is prevented, and the slab having satisfactory internal quality can be inexpensively cast. COPYRIGHT: (C)2011,JPO&INPIT
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