Patent ID: 8376028
Filing Date: 2013-02-19
Classification: B22D

Abstract:
1. A steel continuous casting method using a continuous caster that includes a pair of upper magnetic poles and a pair of lower magnetic poles disposed on outer sides of a mold, the upper magnetic poles facing each other with a mold long side portion therebetween and the lower magnetic poles facing each other with the mold long side portion therebetween, and an immersion nozzle having a molten steel spout located between a peak position of a DC magnetic field of the upper magnetic poles and a peak position of a DC magnetic field of the lower magnetic poles, the method comprising braking a molten steel flow with the DC magnetic fields respectively applied to the pair of upper magnetic poles and the pair of lower magnetic poles while stirring a molten steel with an AC magnetic field simultaneously applied to the pair of upper magnetic poles, wherein the immersion nozzle is used at an immersion depth (distance from a meniscus to an upper end of the molten steel spout) of 180 mm or more and less than 240 mm, a strength of the AC magnetic field applied to the upper magnetic poles is set to 0.060 to 0.090 T, a strength of a DC magnetic field applied to the upper magnetic poles is set to 0.02 to 0.18 T, a strength of a DC magnetic field applied to the lower magnetic poles is set to 0.30 to 0.45 T, and continuous casting is conducted at casting speeds (a) to (d) below: (a) when a slab width is 950 mm or more and less than 1050 mm, the casting speed is 0.95 m/min or more and less than 1.65 m/min; (b) when a slab width is 1050 mm or more and less than 1250 mm, the casting speed is 0.95 m/min or more and less than 1.45 m/min; (c) when a slab width is 1250 mm or more and less than 1450 mm, the casting speed is 0.95 m/min or more and less than 1.25 m/min; and (d) when a slab width is 1450 mm or more and less than 1750 mm, the casting speed is 0.95 m/min or more and less than 1.05 m/min.