| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method with which crystals inside a high strength steel piece and those in a cast piece skin layer part can be made stable and fine equiaxial crystals.SOLUTION: A continuous casting apparatus having an induction electromagnetic agitator in a range of an in-cast meniscus to 10 m below the cast is used to inject, into the cast, molten steel containing acid soluble Al of 0.03 mass% or less, acid soluble Ti of less than 0.1 mass%, Mg of 0.0003-0.006 mass%, and Ca of 0.0001-0.002, and to add, to the in-cast molten steel, one kind or more of Bi and Sn so as to reach 0.0005-0.01 mass% in total, and the molten steel is cast in a horizontal plane while being swivelled with the induction electromagnetic agitator. Relatively fine oxide and sulfide can uniformly be dispersed in the molten steel by adding Mg and Ca into the cast. Columnar crystals are fragmented into fine equiaxial crystals by adding Bi and Si into the cast mold to perform in-cast electromagnetic agitation.SELECTED DRAWING: Figure 1 |
