A method for high-purification preparation of nickel-based superalloy by electron beam melting technology

Abstract

The invention discloses a method for high-purity preparation of a nickel base high-temperature alloy by using an electronic beam smelting technology. The method comprises the steps of: (S1) preparation of raw materials: (S11) pretreatment; and (S12) charging; (S2) smelting preparation: (S21) prevacuumizing; (S22) high vacuumizing; and (S23) filament preheating; (S3) smelting; and (S4) repeating the step (S3) until the alloy with a needed size is obtained. The method can greatly improve the alloy ingot metallurgy quality, meanwhile, reduces the contents of such micro elements as C, N, P and O in the alloy, increases the yield above 85%, can control the macrosegregation of the alloy in a smaller range to effectively shorten the time of such processes as subsequent heat treatment, and can realize engineering preparation of large ingots.

Description

technical field [0001] The invention relates to a method for high-purification preparation of nickel-based superalloy by electron beam smelting technology. Background technique [0002] Aeroengine is the main bottleneck restricting the development of my country's aviation industry. Advanced aero-engines need to meet the following four important indicators: large thrust-to-weight ratio, high reliability, high working stability and low fuel consumption rate. To obtain a large thrust-to-weight ratio, superalloy materials with advanced properties are one of its main supporting technologies. The important reason for the huge gap between domestic and foreign countries is that the control level of alloy impurity elements produced in China is low and the metallurgical quality is poor. Alloy impurity elements will have a serious impact on the durability and creep properties of superalloys, and their content and quantity must be controlled to the lowest possible level. Therefore, t...

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Problems solved by technology

The refractories used in the vacuum induction melting technology will introduce new impurities, which will lead to melt pollution and finally reside in the ingot, and the ingot grains are coarse and uneven, the solidification segregation is serious, and the shrinkage cavity is large; and as a secondary melting technology Although the advanced ESR and VAR technologies have greatly improved the problems left over by the VIM technology, the ingots produced by them also have many deficiencies.

If the slag of ESR technology absorbs gas, it may react with the melt to generate new impurities; the surface quality of the ingot obtained by VAR is poor, and the internal quality of the alloy ingot is poor because the shrinkage cavity cannot be completely eliminated, and the impurities are decomposed and regenerated, which will still cause Exist in the alloy in the form of dispersed distribution

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