| 摘要 |
A refining method of molten steel is provided to reduce heating time of molten steel and temperature rise of the molten steel by injecting aluminum into molten steel in a primary refining furnace of an electric furnace or a converter before discharging molten steel from the primary refining furnace and injecting aluminum and oxygen into molten steel in a subsequent decompressing process, and a method of producing extra low carbon steel using the refining method of molten steel is provided. A method of producing extra low carbon steel using a refining method of molten steel comprises the steps of: primarily refining molten steel in a primary refining furnace of an electric furnace or a converter, and injecting 1.0 to 2.5 kg of aluminum per ton of molten steel into an upper part of the primarily refined molten steel in the primary refining furnace; discharging molten steel from the primary refining furnace, and supplying aluminum and oxygen into molten steel while molten steel is decarburized in a decompression apparatus to increase temperature of molten steel and decarburize the molten steel at the same time; and deoxidizing the decarburized molten steel with aluminum, and injecting calcium oxide into the deoxidized molten steel to maintain the content of iron oxide(T.Fe)+manganese oxide(MnO) in slag to 8.0% by weight or less, and control a ratio of weight percent of alumina(Al2O3) to that of calcium oxide(CaO) to a range of 0.8 to 2.8. |
