METHOD FOR CONTINUOUSLY CASTING CAST SLAB HAVING LITTLE BLOW HOLE AND STEEL MATERIAL OBTAINED BY WORKING THE CAST SLAB

摘要

PROBLEM TO BE SOLVED: To provide a method for continuously casting a cast slab having little blow hole by which the cast slab having excellent quality is produced by restraining the catch of argon gas in molten steel into a solidified shell by a simple method and at a low cost to prevent the surface defect, and the quality of a steel material obtained by applying a rolling-work to the cast slab can be improved, and to provide the steel material obtained by working the cast slab.;SOLUTION: In the method for continuously casting the cast slab, by which the molten steel having a composition causing crystallization of γ-phase as a primary crystal at the solidification is received into a tundish from a ladle and poured into a water-cooled mold through a nozzle to cast the cast slab, the continuous casting is performed after adjusting the component concentrations in the molten steel so that a Z value calculated with the following formula becomes ≤2,500: Z=Σy(i)×(1-k(i))/k(i)×c(i) [wherein, y(i) is a concentration factor indicating the effect of an (i) element exerted to a surface tension in the molten steel and is a positive value in the case of lowering the surface tension at the addition of the element adding time; k(i) is an equilibrium distribution factor of the (i) element in the molten steel; c(i) is a mass% of the (i) element; and Σ is the total of the constituting elements in the molten steel].;COPYRIGHT: (C)2003,JPO