Nickel-cobalt-based high-temperature alloy welding wire

Abstract

The invention belongs to the field of welding materials, and particularly relates to a precipitation strengthening type nickel-cobalt-based high-temperature alloy welding wire for welding a high-temperature part of an 800-DEG C ultra-supercritical power station. The welding wire is mainly characterized in that Ti / Al is more than or equal to 1.5 and less than or equal to 2, and C / Nb is more than orequal to 0.03. The yield strength of the welding wire at 800 DEG C is not less than 600 MPa. An alloy comprises, by mass percent, 25-30% of Co, 20-23% of Cr, 1.4-1.8% of Al, 2.1-3.6% of Ti, 1.5-2.0%of Nb, 0.5-1.0% of Mo, less than or equal to 0.1% of Si, less than or equal to 0.3% of Mn, less than or equal to 0.01% of Cu, less than or equal to 0.04% of C, less than or equal to 0.003% of B, and the balance of Ni, and no rare earth element is contained. A deposited metal matrix of the welding wire is an austenite (gamma) phase of a disordered face-centered structure, precipitation strengthening phases are a Ni3 (Al, Ti) gamma'phase and a primary carbide NbC, and carbide phases are distributed between crystals. The welding wire fills up the blank in the prior art, has excellent high-temperature performance, can be widely applied to homogeneous and heterogeneous welding of high-temperature alloy parts under the condition of ultra-supercritical water vapor at the temperature of 750-800 DEG C, and can also replace an existing nickel-based / nickel-cobalt-based high-temperature alloy welding wire.

Description

technical field [0001] The invention belongs to the field of welding materials, and in particular relates to a Ni-Cr-Co precipitation-strengthened nickel-cobalt-based superalloy welding wire. Background technique [0002] With the advancement of ultra-supercritical power generation technology above 750 °C, a large number of applications of high-temperature alloy materials in this field have been promoted. Filler. Since the welding joint (weld seam) is the weak link of the key high-temperature components of the power station, the welding filler material of one grade higher than the base metal is usually selected during welding to ensure welding performance and quality. High-temperature alloy welding wire is widely used in welding (including dissimilar welding) of heat-resistant steel in power stations due to its excellent high-temperature comprehensive performance. At present, the welding of candidate materials (such as HAYNES282, INCONEL 740H, etc.) Performance will be re...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a nickel-cobalt-based superalloy welding wire with reasonable composition design and high performance, aiming at the fact that the existing high-temperature alloy welding wire cannot meet the service requirements of power plant boilers above 750°C

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