METHOD OF MAKING VANADIUM-CONTAINING STEEL Russian patent published in 2007 - IPC C21C5/52 

FIELD: ferrous metallurgy; methods of making vanadium-containing steel in electric arc melting furnaces.

SUBSTANCE: steel making process is carried out by series; mass of metal burden of the first heat in series exceeds mass of subsequent heats by 10-20% and mass of burden of the last heat in series is lesser than that of previous heat by 10-20%. Oxidizing process is carried out till concentration of carbon is not lower than 0.10% of low content in finished steel and at temperature which is below liquidus temperature by 180-240°C; at tapping the first melt and subsequent melts, furnace slag flux is cutout and at last heat of series, slag is subjected to deoxidation by coke powder, crushed ferro-silicon in the amount of 0.08-0.10% each and the last melt is tapped into ladle with furnace slag; at tapping all the melts into ladle , solid slag-forming additive is introduced into ladle after it has been filled by ¼ of its height; solid slag-forming additive contains lime and vanadium-containing converter slag at ratio of (1.2-1.9) : (0.5-0.9), respectively in the amount of 1.7-2.8 of mass of molten steel in ladle; if necessary, deoxidizing and alloying agent are added; slag-forming additive, deoxidizing and alloying agents are added before ladle is filled with steel to ¾ of its height. Proposed method ensures reduction of melting time by 18 min; reduction of power requirements by 15 kW/h/ton and reduction of consumption of electrodes by 0.18 kg/t.

EFFECT: enhanced efficiency; enhanced through extraction of vanadium.

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