| 摘要 |
PROBLEM TO BE SOLVED: To provide a mold powder for continuously casting a steel with which cooling performance of a cast slab in a secondary cooling zone can be improved and which has excellent exfoliating property from the cast slab surface drawn out of a mold. SOLUTION: This mold powder contains at least SiO<SB>2</SB>, CaO and Na<SB>2</SB>O and the relation between the SiO<SB>2</SB>content and the Na<SB>2</SB>O content in the mold powder lies in a range satisfying formula (1), 0.65×[%Na<SB>2</SB>O]+25≤[%SiO<SB>2</SB>]≤2.08×[%Na<SB>2</SB>O]+25 and the relation between the basicity (CaO/SiO<SB>2</SB>) of the mold powder and the Na<SB>2</SB>O content lies in the range satisfying formula (2), -0.078×[%Na<SB>2</SB>O]+1.4≤CaO/SiO<SB>2</SB>≤-0.077×[Na<SB>2</SB>O]+1.8...(2) (wherein [%Na<SB>2</SB>O] is Na<SB>2</SB>O content (mass%) in the mold powder and [SiO<SB>2</SB>] is SiO<SB>2</SB>content (mass%) in the mold powder). COPYRIGHT: (C)2006,JPO&NCIPI
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