LOW CARBON STEEL MANUFACTURING METHOD FOR SECURING CLEANLINESS OF MOLTEN STEEL BY ADDING DEOXIDIZER TO MOLTEN STEEL

摘要

PURPOSE: To provide a manufacturing method of low carbon steel, the method capable of reducing generation of nonmetal inclusions, shortening refining time and improving quality of molten steel through flotation of the nonmetal inclusions in molten steel by adding aluminum as a deoxidizer to molten steel in a process of refining molten steel in converter. CONSTITUTION: The manufacturing method of low carbon steel comprises the steps of performing soft deoxidation by injecting 200 to 350 kg of Al into a converter containing molten low carbon steel comprising 150 to 500 ppm of carbon and 0.020 to 0.050 wt.% of aluminum when content of terminal oxygen is 300 to 700 ppm in the steelmaking process; and manufacturing the low carbon steel by injecting 60 to 200 kg of Al into the soft deoxidation performed molten steel when content of oxygen before deoxidation is 1 to 150 ppm in the RH process and performing reflux operation on the Al injected molten steel for 1 to 7 minutes.