RAIL STEEL MELTING METHOD Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy, in particular, melting of rail steel in electric arc steel-making furnaces.

SUBSTANCE: method involves feeding into furnace of metal burden, such as metal scraps and liquid cast iron; melting; providing oxidizing period, with following reduction of steel in furnace by aluminum used in an amount of 0.07-0.10% by weight of metal burden and of slag by powdered coke, ground ferrosilicon and granular aluminum, with each of said components being used in an amount of 0.09-0.10% by weight of metal burden; discharging melt into ladle while adding therein of solid slag-forming mixture including lame and fluorspar used in the ratio of (1.0-1.5):(0.3-0.5), respectively, in an amount of 3-3.3% by weight of liquid steel and required reducing agents and alloying additives; providing in-series melting of steel, with weight of first melting metal burden in series exceeding weight of metal burden of subsequent melting processes by 10-15% and weight of finishing melting process being reduced by 10-15%; providing oxidizing period until carbon content is at least 0.60% and temperature is higher than liquidus temperature by 180-240⁰C; performing slag reduction in furnace during finishing melting process in series; during discharge of first and subsequent melting processes, cutting-off furnace slag and discharging final melt with furnace slag.

EFFECT: reduced melting time, power and electrode consumption, reduced concentration of oxygen and phosphor in steel and decreased contamination of steel with non-metallic inclusions.

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