A nickel-based alloy welding wire with recrystallizable weld deposit metal

Abstract

The invention belongs to the field of ultra-supercritical power station welding materials and particularly relates to a solution strengthening type nickel base alloy welding wire high in plasticity. The solution strengthening type nickel base alloy welding wire is suitable for welding of ultra-supercritical boiler superheaters / reheater pipes, welding between the superheaters and boiler gas collection headers (including connecting pipe seats) and welding between the reheater pipes and the boiler gas collection headers (including the connecting pipe seats). The solution strengthening type nickel base alloy welding wire is mainly characterized in that after the welding wire is used in welding conducted through TIG welding (argon tungsten-arc welding), weld deposit metal can be recrystallized after being subjected to postweld heat treatment at the temperature of 1000 DEG C or higher, and dendrite and columnar crystal tissue in an original weld is removed; the hardness of a weld area after welding is 300 HV, and the hardness is reduced to 210 HV after recrystallization; and weld residual stress and component segregation are eliminated, and the welding wire is basically consistent with base metal in appearance. The chemical components of the nickel base alloy welding wire include, by weight percent, smaller than 3% of Fe, 14%-18% of Cr, smaller than or equal to 0.45% of Al and Ti, smaller than 0.9% of Ti / Al, 1.0%-1.5% of Nb, 7.0%-9.8% of Mo, smaller than 0.4% of W, smaller than or equal to 1.0% of Si, 0.5%-1.0% of Mn, smaller than or equal to 0.1% of C, 0.003%-0.005% of B, smaller than or equal to 0.03% of Zr, the balance Ni and smaller than 0.1% of the sum of other impurity elements.

Description

Technical field: [0001] The invention belongs to the field of welding materials for ultra-supercritical power stations, and in particular relates to a nickel-based alloy welding wire with recrystallized weld deposited metal. Background technique: [0002] With the development of thermal power generation technology, the development of ultra-supercritical coal-fired power generation technology at 600°C and above has very important strategic significance and practical application value for my country to save energy and reduce pollutants and carbon dioxide emissions. The welding of high-temperature materials for power stations has always been a key technical link in the construction and production of power stations. The continuous improvement of steam parameters and the continuous improvement of the degree of alloying of the high-temperature materials used have made the large-scale use of austenitic stainless steel and nickel-based alloys, making the welding technology difficult. Inc...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a welding seam for the existing ultra-supercritical power plant boiler superheater / reheater tube welding joints with large residual stress, serious composition segregation, and obvious solidified (cast) state structure in the weld zone. Deposit metal recrystallized nickel base alloy welding wire

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