METHOD OF LIGATURE PRODUCTION IN VACUUM ARC FURNACE WITH NON-CONSUMABLE ELECTRODE Russian patent published in 2020 - IPC C22C35/00 C22B9/20 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to production of ligatures in vacuum arc furnace with non-consumable tungsten electrode. Ligature production method, which includes loading of charge materials into a copper water-cooled crystallizer placed in a melting chamber of a vacuum arc furnace with a non-consumable tungsten electrode, closing a melting furnace chamber, air pumping-out and inert gas inlet into furnace smelting chamber, primary melting of charge materials by electric arc, inverting obtained ingot and its repeated remelting. In primary melting, charge materials are used which include all alloying elements included in the ligature, pumping air from the melting furnace chamber to residual pressure of not more than 1.5⋅10^-3 mm Hg, inert gas is fed into furnace melting chamber to pressure in range from 50 to 750 mm Hg, primary melting of charge materials and repeated remelting of ingot is started at value of arc current in range from 20 to 400 A, and then it is increased to values in range from 150 to 1250 A.

EFFECT: wider range of obtained ligatures of high homogeneity and low content of gases - oxygen and nitrogen.

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