Ni-based single crystal superalloy and alloy member using the same as base

Abstract

Disclosed is a Ni-based single crystal superalloy having a composition consisting of, in mass percent, 5.0-7.0% of Al, 4.0-8.0% of Ta, 0-2.0% of Mo, 3.0-8.0% of W, 3.0-8.0% of Re, 0-0.50% of Hf, 3.0-6.0% of Cr, 0-9.9% of Co, 1.0-14.0% of Ru, 0.1-4.0% of Nb and the balance of Ni and unavoidable impurities. The present invention provides a Ni-based single crystal superalloy which suppresses the precipitation of the TCP phase at high temperatures, improves strength at high temperatures, and has oxidation resistance at high temperatures. The inventon aims to provide a Ni-based single crystal superalloy of high performance in strength and oxidation resistance at high temperatures, and further aims to provide a Ni-based single crystal superalloy having sufficient characteristic in a ''heat treatment window'' of not being negligent at the practical aspect.

Description

technical field [0001] The invention relates to a Ni-based single crystal superalloy with Al, Ta, W, Re, Cr, Ru and Nb as main additive elements and an alloy component based on it, especially to improving its high-temperature creep characteristics and high-temperature corrosion resistance Environmentally resistant technology. Background technique [0002] Among the typical compositions of Ni-based single crystal superalloys developed as materials for dynamic and stationary wings at high temperatures such as aircrafts and gas turbines, the compositions shown in Table 1 are listed, for example. [0003] 【Table 1】 [0004] [0005] In the above Ni-based single crystal superalloy, the Ni-based single crystal superalloy is obtained by performing a solution (Japanese: solution) treatment at a predetermined temperature and then performing an aging treatment. This alloy is called a so-called precipitation-solidified alloy, and has a form in which a γ' phase as a precipitate pha...

AI Technical Summary

Problems solved by technology

However, since the composition ratio of Re (5% by mass or more) exceeds the amount of Re solid solution in the parent phase (γ phase), there is a problem that the remaining Re combines with other elements to precipitate a so-called TCP phase (Topologically Closed phase) at high temperature. 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 high-temperature life, 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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