| 摘要 |
PROBLEM TO BE SOLVED: To prevent the development of longitudinal crack and breakout even under high speed casting by arranging high frequency induction coil at the upper part of a meniscus in a mold, conducting current in specific range of frequency and density into powder pool to heat the powder and thinning and uniformizing the thickness of slag rim. SOLUTION: The current having 50k-500kHZ frequency and 1×10<6> -2×10<6> AT/m<2> current density, is conducted into the powder pool from the high frequency induction coil 8 to heat the powder. The high frequency induction coil 8 is arranged above the powder fused layer 4 at <=200mm from the surface of molten steel 5 and at above 200mm from the upper surface of the powder layer. Further, the distance between the side surface of the high frequency induction coil 8 and the inner wall surface of the mold, is made to 5-50mm. Since the surface level of the molten steel 5 is varied in some case, the coil is shifted in the vertical direction by linking with a molten steel surface level sensor and the distance between the powder fused layer 4 and the high frequency induction coil 8 can be held to the constant.
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