Method for Producing Al-Killed Steel with High Cleanliness

摘要

PURPOSE: A method for producing Al-killed steel with high cleanliness by performing pressure reduction or vacuum treatment on the molten Al-killed steel after feeding a flux-cored wire comprising calcium oxide, aluminum oxide and metal magnesium into molten Al-killed steel is provided. CONSTITUTION: The method comprises a step of deoxidizing molten steel with aluminum during tapping after performing first refining in converter or electric furnace, or deoxidizing molten steel with aluminum in second refining process such as vacuum refining; a step of feeding a flux-cored wire comprising calcium oxide, aluminum oxide, metal magnesium having 3 to 10 wt.% of the sum of the calcium oxide and aluminum oxide and inner flux material in which a weight ratio of the calcium oxide to the aluminum oxide is 65 to 35 : 35 to 65 into the molten Al-killed steel; and a step of performing pressure reduction or vacuum treatment on the molten Al-killed steel after the step of feeding a flux-cored wire into the molten Al-killed steel, wherein the inner flux material comprises 32 to 63 wt.% of calcium oxide, 32 to 63 wt.% of aluminum oxide and 3 to 9 wt.% of metal aluminum.