Nickel iron based welding wire for boiler of 700 DEG C ultra-supercritical power station

Abstract

The invention discloses a nickel iron based welding wire for a boiler of a 700 DEG C ultra-supercritical power station, and belongs to the field of welding materials of ultra-supercritical power stations. The nickel iron based welding wire is prepared through the following components in percentage by mass: 23-30% of Fe, 19-24% of Cr, 1.8-2.4% of Al, 2.0-2.5% of Ti, 3.0-5.2% of Mo, less than 0.4% of W, not greater than 0.15% of Si, 0.4-0.8% of Mn, 0.04-0.07% of C, 0.001-0.003% of B, not greater than 0.02% of Zr, and the balance Ni, wherein Ti / Al is not less than 1; the sum of other impure elements is less than 0.1%. According to the nickel iron based welding wire, a weld joint can be microalloyed after welding through TIG (argon tungsten-arc welding), and thus the obtained weld joint meetsthe standard requirement; a weld joint area substrate formed by the nickel iron based welding wire is an austenite (gamma) phase of an irregular surface-core structure; the precipitate reinforcing phase is gamma' (Ni3(Al, Ti)) phase; and carbide phases are distributed among crystals.

Description

technical field [0001] The invention belongs to the field of ultra-supercritical power station welding materials, and in particular relates to a nickel-iron-based welding wire for a 700°C ultra-supercritical power station boiler. Background technique [0002] With the development of thermal power generation technology, the development of 700°C advanced ultra-supercritical (A-USC) coal-fired power generation technology has very important strategic significance and practical application value for my country's energy conservation, reduction of pollutants and carbon dioxide emissions. The welding of high-temperature materials in power stations has always been a key technical link in the construction and production of power stations. With the continuous improvement of steam parameters, the amount of high-alloyed high-temperature materials used has continued to increase, especially the nickel (iron) base and nickel in the key components of power station boilers. The extensive use ...

AI Technical Summary

Problems solved by technology

The mass fraction of Fe element in nickel-iron-based welding wire (such as ERNiCrFe-3, ERNiCrFe-7) commonly used in power plant boilers does not exceed 12%, and the cost advantage is not obvious; and due to the increase of Fe element content, the γ′( Ni 3 (Al,Ti)) The volume fraction of the precipitation strengthening phase, so the precipitation strengthening effect is not as good as that of nickel-based alloys

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