METHOD FOR SMELTING CORROSION-RESISTANT STEEL IN DC ELECTRIC ARC STEELMAKING FURNACE WITH HOLLOW GRAPHITE ELECTRODE Russian patent published in 2023 - IPC C21C5/52 C21C5/30 C21C7/72 

FIELD: metallurgy.

SUBSTANCE: smelting of corrosion-resistant steels in DC electric arc steelmaking furnaces with a hollow graphite electrode. The oxidation period of melting is carried out by conducting argon-oxygen purge through a hollow graphite electrode directly into the arc to obtain low-temperature plasma. The argon content during purge is 70±5 vol.%, and the rest is oxygen up to the achievement of a carbon concentration in steel of 0.15-0.12 wt.%. In the concentration range for carbon 0.09-0.10 wt.% it is necessary to change the ratio of argon to oxygen in the blast to a value of 87±2/13±2 vol.%. At the final stage of oxidative purge - in the range of carbon concentrations from 0.10 wt.% to branded content. Argon/oxygen ratio should be 95±1/5±1 vol.%.

EFFECT: intensifying the process of steel smelting in furnaces with a capacity of 0.01 to 5 tons, reducing chromium loss by increasing the oxidizing potential of the gas mixture, and also creating favorable thermodynamic conditions for selective decarburization.

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