IMMERSION NOZZLE FOR CONTINUOUS CASTING, RESTRAINING DEVELOPMENT OF SURFACE DEFECT AND INTERNAL DEFECT AND CONTINUOUS CASTING METHOD USING THIS NOZZLE FOR CONTINUOUS CASTING

摘要

PROBLEM TO BE SOLVED: To provide an immersion nozzle for continuous casting with which development of surface defect and internal defect of a cast slab can be restrained, and a continuous casting method using this nozzle.;SOLUTION: In the immersion nozzle 1 for continuous casting, supplying one pair of side part discharging holes arranged on the side parts at the tip part of a cylindrical body and a bottom part discharging hole arranged at the bottom part, a casting velocity Vc (m/min) and a ratio (%) of the cross sectional area S₂ of the bottom part discharging hole 3 to the total cross sectional area S₁ of the above side part discharging holes 2 and the bottom part discharging hole 3, satisfy 6 (%)S₂/S₁10 (%) and 0.6 (m/min)Vc1.8 (m/min). The side part discharging holes are arranged in the range of 5° to 25° angle downward to the center of the immersion nozzle, and the bottom part discharging hole 3 is formed as a circle shape or an elliptic shape.;COPYRIGHT: (C)2004,JPO