| 摘要 |
PROBLEM TO BE SOLVED: To provide a continuous casting method for steel which improves the problem that inert gas bubbles discharged from the inside of an immersion nozzle are made into small bubbles poor in floating-up properties owing to the reduction in the runoff rate of inert gas from the inside of the immersion nozzle, thus the effect of floating-up and separating fine inclusions in the molten steel within a mold can not be sufficiently obtained, and slivering is frequently generated owing to the remaining fine inclusions in the molten steel. SOLUTION: In the continuous casting method where, when a molten steel is continuously poured from a tundish into a mold via an immersion nozzle, inert gas is blown into the immersion nozzle, bubbles are discharged from a gas permeable refractory composing the inner circumferential part of the immersion nozzle so as to prevent the clogging of the immersion nozzle, an immersion nozzle in which the runoff rate (B) of the inert gas from an inner hole body part 3 located at the inside of the immersion nozzle occupied in the whole quantity (A) of the feed of the inert gas fed into the immersion nozzle satisfies 0.8≤B/A≤0.95 is used. COPYRIGHT: (C)2010,JPO&INPIT
|
