Ni-based single crystal superalloy and alloy member obtained from the same

Abstract

Provided is an Ni-based single crystal superalloy wherein the ingredients have a composition containing, as ratio by mass, from 5.0% by mass to 7.0% by mass of Al, from 4.0% by mass to 8.0% by mass of Ta, from 0% by mass to 2.0% by mass of Mo, from 3.0% by mass to 8.0% by mass of W, from 3.0% by mass to 8.0% by mass of Re, from 0% by mass to 0.50% by mass of Hf, from 3.0% by mass to 7.0% by mass of Cr, from 0% by mass to 9.9% by mass of Co and from 1.0% by mass to 10.0% by mass of Ru, with the balance of Ni and inevitable impurities. The alloy prevents TCP phase precipitation at high temperatures, therefore having improved strength at high temperatures and having oxidation resistance at high temperatures. The above-mentioned first-generation alloy CMSX-2 and second-generation alloy CMSX-4 are, though comparable thereto in point of creep strength at low temperatures, inferior to third-generation alloys in point of creep strength at high temperatures, since a large quantity of eutectic ³'-phase remains therein even after high-temperature solution treatment.

Description

[0001] This application is a divisional application of the application with the application number 200980124215.1 and the invention title of "Ni-based single crystal superalloy and alloy components obtained therefrom" filed by the applicant on June 26, 2009. Technical field [0002] The invention relates to a new Ni-based single crystal superalloy, which uses Al, Ta, W, Re, Cr and Ru as main additional elements, and has excellent high-temperature creep characteristics and high-temperature corrosion resistance and other environmental resistance. Background technique [0003] Among the representative compositions of Ni-based single crystal superalloys developed as materials for moving and static blades at high temperatures such as aircraft and gas turbines, for example, the compositions described in Table 1 are cited. [0004] [Table 1] [0005] [0006] In the above-mentioned Ni-based single crystal superalloy, a solution (Japanese: solution) treatment is performed at a predetermined t...

AI Technical Summary

Problems solved by technology

However, since the composition ratio of Re (5% by mass or more) exceeds the solid solution amount of Re in the parent phase (γ phase), there is a problem that the remaining Re combines with other elements to precipitate the so-called TCP phase (Topologically Close Packed phase), and due to long-term use at high temperature, the amount of the TCP phase increases and the creep strength decreases

As shown in the above examples, it is difficult to develop Ni-based single crystal superalloys that have both life at high temperatures, strength, and oxidation resistance, and this will become an important technical problem for the practical use of heat-resistant alloys in the future.

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