PRODUCTION OF NITROGEN-CONTAINING LOW CARBON STAINLESS STEEL

摘要

PURPOSE:To produce easily nitrogen-contg. low carbon stainless steel in the stage of decarburization and refining of low carbon stainless steel by top blowing of pure oxygen by blowing a gaseous mixture of oxygen and nitrogen when the content of C in molten steel attains a specific value or below. CONSTITUTION:Decarburization and refining by pure oxygen are suspended and a gaseous mixture of oxygen and nitrogen is blown into a vacuum vessel from the bottom thereof at the point of the time when the content of C in molten stainless steel attains about 0.1% on progression of decarburization reaction in the stage of producing stainless steel by decarburizing and refining by pure oxygen in the vacuum vessel. The C in the molten metal is removed down to the content as low as 0.04-0.01% by the refining operation and nitrogen is absorbed and incorporated thereon up to the saturation amt. determined by the degree of vacuum in the refining atmosphere, the compsn. of the molten stainless steel and the temp. of the molten steel at that time. The nitrogen-contg. low carbon stainless steel is produced easily by this method while decreasing the oxidation loss of Cr in the decarburization after <0.1% C.