PRODUCTION METHOD FOR LOW CARBON MOLTEN STEEL USING VACUUM DEGASSING AND DECARBURIZATION TREATMENT

摘要

In a vacuum degassing and decarburization treatment,the present invention uses a CO2 gas as a recirculatinggas and as a stirring gas without inviting stoppage ofdecarburization and an increase in the carbonconcentration and moreover, without an increase in theamount of addition of an alloy, and can reduce the gascost.The present invention provides a production methodfor a low carbon molten steel which comprises blowing aCO2 gas from the start of degassing treatment till thecarbon concentration of the molten steel reaches 50 ppmin vacuum degassing and decarburization treatment of themolten steel, and thereafter blowing an Ar gas.