Immersion nozzle for continuous casting and continuous casting method using the immersion nozzle

摘要

An immersion nozzle for continuous casting which enables improvement in quality of a slab surface and increase in the efficiency of casting by suppressing the self-excited oscillation of a flow in a mold without using a complicated mechanism such as a swirl flow generating immersion nozzle is to be provided. A first immersion nozzle for continuous casting is a nozzle comprising a cylindrical body and a pair of outlet ports formed to face each other in a side wall in the vicinity of a bottom part of the cylindrical body, wherein a ridge-shaped projection extending parallel with the discharge direction projected on a cross section of the nozzle is formed on an inner surface of the bottom part, which is formed in a waterfall basin-like recessed shape having a maximum depth of 5 mm to 50 mm. A second immersion nozzle for continuous casting is a nozzle comprising a cylindrical body and a pair of outlet ports formed to face each other in a side wall in the vicinity of a bottom part of the cylindrical body, wherein each sectional area of the outlet ports vertical to a discharge direction projected on a cross section or longitudinal section of the nozzle is decreased toward an exit.