CONTINUOUS CASTING METHOD OF ULTRA LOW CARBON ALUMINUM LESS TITANIUM DEOXIDIZED STEEL

摘要

PROBLEM TO BE SOLVED: To realize the mass production by preventing the nozzle clogging of ultra low carbon Al-less Ti deoxidized steel with less silver defects in the continuous casting. SOLUTION: Impurities including bubbles moving to the center part and fine impurities are separated through collision and collection by controlling the cleanliness of the molten steel in the ladle so that the number of impurities of >=10μm in size in the molten steel in the ladle is preferably >=6/cm<2> , or the total oxygen content is preferably >=60ppm to prevent a ladle nozzle from being clogged, blowing the inert gas immediately before a dipping nozzle from a furnace wall while the rotational movement is given to the molten steel, and centrifugally separating the blown inert gas. The clean molten steel is fed to a mold to continuously cast the ultra low carbon Al-less Ti deoxidized steel with less surface defects.