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 CO.sub.2 gas as a recirculating gas and as a stirring gas without inviting stoppage of decarburization and an increase in the carbon concentration and moreover, without an increase in the amount of addition of an alloy, and can reduce the gas cost. The present invention provides a production method for a low carbon molten steel which comprises blowing a CO.sub.2 gas from the start of degassing treatment till the carbon concentration of the molten steel reaches 50 ppm in vacuum degassing and decarburization treatment of the molten steel, and thereafter blowing an Ar gas.