Mn and Nb added NiCrFe alloy surfacing solder strip for nuclear power and welding method

Abstract

The invention provides a Mn and Nb added NiCrFe alloy surfacing solder strip for nuclear power and a welding method and belongs to NiCrFe nickel base alloy solder strips. The solder strip is composed of, by weight, less than 0.04% of C, less than 0.50% of Si, less than 5.0% of Mn, less than 0.015% of S, less than 0.020% of P, 28.0-31.5% of Cr, 7.0-12.0% of Fe, less than 2.5% of Nb, less than 0.30% of Cu, less than 0.50% of Al, less than 0.50% of Ti, and the balance nickel. The Mn and Nb added NiCrFe alloy surfacing solder strip for nuclear power can be applicable to a submerged arc overlay welding process and an electroslag surfacing process and can also be applicable to manufacturing of key components of a nuclear island of a nuclear power plant by being matched with corresponding soldering flux, the Mn element and the Nb element are added in the solder strip and improve the performance of resistance to high temperature plasticity-losing cracks of surfacing deposited metal, the surfacing deposited metal has high crystallization crack resistance and stress corrosion cracking resistance, the excellent corrosion resistance is achieved and integrated mechanical performance is good. By being matched with the soldering flux for surfacing, a weld pass is attractive in formation, corrugations are compact, deslagging is easy and welding defects are avoided.

Description

technical field [0001] The invention relates to a welding material, in particular to a NiCrFe type nickel base alloy welding strip. Background technique [0002] With the country listing nuclear power as an important direction for future energy upgrading and transformation and the rapid development of nuclear power technology in the world, the third-generation passive nuclear power technology represented by AP1000 has begun to occupy a dominant position, and the key components of the nuclear island of nuclear power plants are gradually becoming larger. Reactor pressure vessels, steam generators, pressurizers and other pressure vessels are increasingly demanding. As the hub of energy exchange in nuclear power plants, steam generators are required to be surfacing with nickel-based alloys on the primary side of the tube plate at the boundary of the primary circuit of the nuclear island. Achieve quality requirements such as corrosion resistance and high temperature resistance. ...

AI Technical Summary

Problems solved by technology

[0008] The main difficulty in nickel-based alloy welding is that nickel-based alloys are highly sensitive to thermal cracks, and it is difficult to control small cracks such as high-temperature plastic loss cracks, crystallization cracks, and stress corrosion cracks. Currently, they are widely used in nuclear power plant steam generator tube plate surfacing welding. The most important is the improved NiCrFe alloy welding strip. The improved NiCrFe alloy is developed on the basis of the traditional NiCrFe alloy. The improved NiCrFe alloy significantly improves the ability of the surfacing layer to resist high temperature plastic cracking, but it still has a high Crack sensitivity cannot fully meet the welding requirements of steam generator tube sheets

The tensile strength of NiCrFe-type alloy welding strip electroslag surfacing is low, which cannot meet the current mainstream technical index requirements

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