Nickel-based deformed superalloy with high aluminum content and preparation method thereof

Abstract

The invention provides a nickel-based deformed superalloy with high aluminum content and a preparation method thereof. A traditional Ni-Co-Cr component serves as a matrix element, the content of the alloy element is increased, particularly, the content of a solid solution strengthening phase gamma'phase forming element Al is increased, the content of a strengthening phase gamma'phase is increasedto 55%-65%, and the temperature bearing capacity of the alloy is effectively improved. A proper amount of Nb element is added into the alloy, so that the stability of a gamma'phase can be improved, the casting-forging process performance is further improved, the long-time structure stability of the alloy at 850 DEG C can be improved by reducing the addition of Cr element, and the surface stabilityloss caused by the reduction of the Cr element can be compensated by the high-content Al element. Meanwhile, a duplex technology or a triple technology is adopted for preparing and machining an alloyraw material, the obtained nickel-based deformed superalloy solves the problem that no high-performance wheel disc forge piece material capable of being used at 850 DEG C for a long time exists at present, and the nickel-based deformed superalloy particularly has excellent tensile strength and yield strength and long service life at 850 DEG C.

Description

technical field [0001] The invention belongs to the field of alloy preparation, and in particular relates to a high-aluminum-content nickel-based deformed superalloy and a preparation method thereof. Background technique [0002] The service temperature of advanced gas turbine engines, such as high-pressure compressor discs such as aero engines and gas turbines, and hot-end rotating discs such as turbine discs, has gradually increased, and the long-term service temperature can reach up to 850 °C. The alloy materials required for wheel forgings are required to have excellent strength and plasticity at room temperature to 850°C, high-temperature durable creep properties, and long-term microstructure and performance stability, as well as good casting and forging process performance. [0003] At present, the largest amount of nickel-based deformed superalloy wheel materials used in domestic aero-engines is the GH4169 alloy used below 650°C, and the highest use temperature is GH4...

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Problems solved by technology

[0003] At present, the largest amount of nickel-based deformed superalloy wheel materials used in domestic aero-engines is the GH4169 alloy used below 650°C, and the highest use temperature is GH4720Li, GH4065A, GH4738 and other nickel-based deformed superalloy wheel materials used below 750°C , There are nickel-based deformed superalloy wheel materials such as GH4141 and GH4586 that can be used for a short time below 850°C, but they cannot meet the long-term use requirements above 850°C

[0004] As we all know, the most effective way to increase the service temperature of nickel-based superalloys is to increase the degree of alloying and increase the content of the strengthening phase γ′ phase. However, if the degree of alloying is too high, the metallurgical segregation tendency of the alloy will be large and the thermoplasticity will be poor. Therefore, the development of new Nickel-based wrought high-temperature alloy wheel materials are quite difficult. In terms of composition design, it is not only necessary to improve the comprehensive performance of alloying to meet the needs, but also to combine the existing technical conditions to make it have certain process performance to ensure manufacturability.

Traditional nickel-based superalloys with a γ′ phase content of 55-65% can only be produced by powder metallurgy or casting (including equiaxed casting, directional solidification and single crystal solidification). These alloys are produced by casting-forging processes. Due to the problems of large element segregation tendency, easy formation of metallurgical defects, and poor plasticity during hot working (forging), this type of alloy composition is not suitable for the preparation of nickel-based deformed superalloy wheel materials.

In addition, although the service temperature of some nickel-based superalloys prepared by powder metallurgy or casting process can reach 850 °C, their microstructure uniformity and compactness are not as good as forgings produced by casting-forging process.

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