| 摘要 |
The purpose of the present invention is to provide a mold flux which is capable of preventing the occurrence of a longitudinal crack in the surface of a cast slab during continuous casting of a sub-peritectic steel that contains Ti. A mold flux according to the present invention is mainly composed of CaO, SiO2, an oxide of an alkali metal and a fluorine compound, and has f(1) of from (1.1 - 0.5 × T) to (1.9 - 0.5 × T), f(2) of from 0.05 to 0.40 and f(3) of from 0 to 0.40 as calculated from the initial chemical composition, if T is the Ti content (mass%) in a molten steel. The content ratio of TiO2 in a molten state during the casting is 20% by mass or less, and the ratio of the first peak intensity of perovskite to the first peak intensity of cuspidine in a mold flux film is 1.0 or less. |
