METHOD FOR CONTINUOUSLY CASTING EXTREMELY LOW CARBON STEEL

PURPOSE:To restrain the development of blister flaw by restraining invasion of Al2O3 series inclusion into a mold at the time of continuously casting. CONSTITUTION:At the time of continuously casting an extremely low carbon steel, related to Mn yield [Mn] (Mn content at the time of steel-tapping/Mn content before blowing) in a converter or sum [FeO+MnO] of FeO content and MnO content after vacuum degassing treatment, a leaning flow degree sigmaH in the mold is controlled so as to satisfy the following inequalities (1) or (2). 4.5-sigmaH>=25.08X{[Mn]-20}... (1), 3.1-sigmaH>=3.962-{29-[FeO+ MnO]}... (2) Wherein, sigmaH: standard deviation of H=K(TL-TR)X100, TL: water temp. difference between inlet and outlet at left short side wall in the mold, TR: water temp. difference between inlet and outlet at right short side wall in the mold, K: constant (or function of TL and TR).