Cobalt-based high-temperature alloy and preparation method thereof

Abstract

The invention belongs to the field of high-temperature alloys, and particularly relates to a gamma' phase reinforced cobalt-based high-temperature alloy with high-stability structure and good oxidation resistance. The gamma' phase reinforced cobalt-based high-temperature alloy comprise the following chemical components of, by weight, 2.5-4% of Al, 3-10% of W, 0.5-5% of Ti, 1.5-6% of Ta, 18-35% ofNi, 10-14% of Cr, 0-4.5% of Nb, 0-0.5% of Hf, 0-0.1% of C, 0-0.1% of B, 0-0.1% of Zr, 0-0.5% of Si, and the balance Co, and the contents of Al plus Cr is more than or equal to 13.5%, the Al plus the Ti plus the Ta plus the Nb are more than or equal to 9.5%, and the W plus the Ta is less than or equal to 12.5%; and a vacuum arc furnace is adopted for smelting, then solid solution is carried out atthe temperature of 1200-1250 DEG C, and aging heat treatment is carried out at the temperature of 700-900 DEG C. The gamma / gamma' two-phase structure stably exists at the temperature of 700-900 DEG C,and the gamma' strengthening phase volume fraction is larger than 40%; and meanwhile, the alloy has good oxidation resistance, large hot working window and low alloy density, and is an alternative material of a high-temperature disc piece of an aero-engine and an industrial gas turbine.

Description

technical field [0001] The invention belongs to the technical field of superalloys, and relates to a gamma' phase-strengthened cobalt-based superalloy with high structural stability and good oxidation resistance and a preparation method thereof. Background technique [0002] Superalloys have high high temperature strength, excellent creep and fatigue resistance, good oxidation and corrosion resistance, structural stability and service reliability, so they have become irreplaceable key materials for hot end parts of aero engines and industrial gas turbines. From the 1930s to the 1950s, cobalt-based superalloys with solid solution strengthening and carbide strengthening were developed, and were first applied in the hot end parts of aero-engines. Compared with nickel-based superalloys, cobalt-based superalloys have higher melting points, better thermal corrosion resistance, thermal fatigue resistance and welding performance. However, due to the lack of L1 in traditional cobalt...

AI Technical Summary

Problems solved by technology

The composition characteristics of the cobalt-based deformed alloy of Fu Huadong's research group in China emphasize the role of the alloy element Mo, and replace part of the W element with Mo to reduce the alloy density. However, it is well known that Mo is not good for the high-temperature oxidation resistance of the alloy [Fu Hua Dong, Xie Jianxin, Zhang Yi, A cobalt-based superalloy with low density and high structural stability and its preparation method]

[0005] In summary, although some multi-element cobalt-based wrought superalloy compositions have been reported, these alloy compositions are more for a single performance, resulting in the overall performance of these alloys is not the best, and the application is limited

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