| 摘要 |
PROBLEM TO BE SOLVED: To optimize the impressing condition of an electromagnetic force and to obtain fine structure in a cast slab by supplying AC current to an electromagnetic coil disposed in a course for carrying the cast slab drawn from a mold in a specific range of temp. gradient at the solidified interface in the cast slab. SOLUTION: Desirably, the AC current is supplied to the electromagnetic coil arranged in a mold for continuous casting at the position except a meniscus part or at the meniscus position in the range of 1-100 deg.C/mm temp. gradient at the solidified interface in the cast slab. Plural sets of the electromagnetic coils are independently constituted. Further, desirably, the frequency of the AC current is regulated so as to satisfy the inequality 1 (Hz)<=f<=1/πμσ.d<2> (wherein, (f) is frequency,μis magnetic permeability,σis electric conductivity and (d) is solidified shell thickness at the coil position). Molten steel held in a tundish 1 is poured into the mold 2 and shifted downward and cooled and carried with continuous casting rolls 4 to make the cast slab 7. In this way, the structure at the position of the electromagnetic coil 3 is made fine to improve the quality of the cast slab.
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