CONTINUOUS CASTING METHOD OF BI FREE CUTTING STEEL

PURPOSE: A continuous casting method of Bi free cutting steel is provided, in which blow hole is effectively restrained by regulating the horizontal eject angle of a submerged entry nozzle, in place of using electromagnetic agitator. CONSTITUTION: In a continuous casting method of Bi free cutting steel comprising C0.03-0.15 wt.%, Si 0.3 wt.% or less, Mn 0.9-1.4 wt.%, P 0.05-0.12 wt.%, S 0.25-0.35 wt.%, Bi 0.03-0.2 wt.%, Al 0.005 wt.% or less, N 50-100ppm, dissolved oxygen 20-100 ppm, a balance of Fe and other inevitable impurities, the present method is characterized in that a stopper comprising alumina, carbon and 15-35 wt.% of aluminum carbide for tundish flow control is used so that formation of inclusions and carburizing of molten steel are minimized. In addition, the horizontal eject angle of a submerged entry nozzle is regulated between 15 and 30 degrees so that the formation of blow hole is restrained.