RH REFINING METHOD FOR MANUFACTURING ULTRA-LOW-CARBON STEEL

摘要

PURPOSE: A vacuum circulation degassing refining method for low-carbon steel manufacturing is provided to increase the cleanliness of molten steel by floating deoxidation inclusion and complex oxide in the molten steel to be efficiently removed. CONSTITUTION: A vacuum circulation degassing refining method for low-carbon steel manufacturing comprises the following steps. Decaburization treatment is performed by controlling a reflux gas flow rate and the degree of vacuum(S1). An additive mixed with a manganese metal compound and a silicon metal compound is injected into molten steel(S2). A deoxidizer is injected to remove oxygen ingredients which are left in the molten steel(S3). A complex oxide is generated by the reaction between the additive and the deoxidizer which are injected into the molten steel, and the complex oxide is floated onto the upper part of the molten steel(S4). [Reference numerals] (AA) Start; (BB) End; (S1) Step of performing decarburization treatment; (S2) Step of injecting an additive; (S3) Step of injecting a deoxidizer; (S4) Step of letting a complex oxide float;