PRODUCTION METHOD OF CARBON-FREE FOUNDRY HEAT-RESISTANT NICKEL-BASED ALLOYS Russian patent published in 2019 - IPC C22C1/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to production of carbon-free foundry heat-resistant nickel-based alloys, and can be used in production of blanks for casting articles, mainly, single-crystal working blades of gas turbine engines. Method for production of carbon-free foundry heat-resistant alloys on nickel base includes melting of metal stock consisting of wastes, high-temperature refining of melt in vacuum at temperature 1,500–1,700 °C, introduction of calcium and at least one rare-earth metal. High-temperature refining is carried out for 10 to 20 minutes, calcium and at least one rare-earth metal is introduced in two steps, at first of which calcium is introduced into melt in amount of 0.025–0.10 % of metal charge weight under inert gas pressure of 40–100 mm Hg, vacuum is created and at least one rare-earth metal is introduced in amount of 0.001–0.05 % of metal charge mass. At the second step, calcium is added to the melt in vacuum in amount of 0.005–0.02 % of the weight of the metal charge and at least one rare-earth metal in amount of 0.06–0.50 % of the weight of the metal charge.

EFFECT: higher heat resistance of obtained alloy due to reduced content of harmful impurities of oxygen, nitrogen and sulfur.

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