A kind of iron-nickel-based solder for high temperature brazing

Abstract

The invention provides Fe-Ni based brazing filler metal for high-temperature brazing. The Fe-Ni based brazing filler metal comprises chemical compositions by weight: 20.0-24.0% of Ni, 5.0-10.0% of Cr, 3.0-7.0% of Si, 1.5-3.5% of B, 2.0-10.0% of Cu, 0.5-3.0% of Ti and the balance Fe. The Fe-Ni based brazing filler metal has the advantages that the cost is low and the strength of a brazing joint is high. The stainless steel brazing joint with high strength is obtained at the brazing temperature of 1090-1120 DEG C, the room temperature strength reaches 320-500MPa, and the room temperature strength of the stainless steel brazing joint is considerably higher than that of a conventional Ni-based brazing filler metal joint and that of a pure copper brazing filler metal joint. If the Fe-Ni based brazing filler metal replaces the traditional Ni-based brazing filler metal to braze structural members like heat exchangers, the problem of low strength of the Ni-based brazing filler metal joint is solved. If the Fe-Ni based brazing filler metal replaces the pure copper brazing filler metal to braze coolers and the like, failure caused by copper loss can be avoided. The Fe-Ni based brazing filler metal is suitable for brazing connection of various stainless steel materials and brazing connection of the stainless steel materials and copper alloy, common carbon steel or Ni-Fe based high-temperature alloy and suitable for brazing connection of common carbon steel or Ni-Fe based high-temperature alloy.

Description

technical field [0001] The invention belongs to the technical field of welding, and relates to an iron-nickel-based solder for high-temperature brazing. Background technique [0002] According to its structure, stainless steel can be divided into ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, austenitic-ferritic stainless steel and precipitation hardening stainless steel. Among various types of stainless steel, austenitic stainless steel is the most widely used and has the most varieties. It is widely used in industrial fields such as architectural decoration, food industry, medical equipment, petroleum, chemical industry, automobile, aviation and aerospace. Brazing technology can be used to connect workpieces of different types, special shapes, and complex structures. The joints have better comprehensive performance, and the brazing productivity is high, and it is easy to realize automatic production. It is the most active professional fi...

AI Technical Summary

Problems solved by technology

The stainless steel oil cooler of the vehicle engine is brazed with pure copper. The brazed joints are prone to corrosion under high temperature and high pressure, which will greatly increase the copper content and particle number in the oil, that is, the phenomenon of "copper loss", which will eventually lead to the failure of the vehicle engine. The wear and temperature rise of parts and components caused engine failure and brought significant economic losses to the enterprise ("Welding", No. 2, 2011, authors Xu Ronghua, Zhang Wenfeng, etc.); use nickel-based brazing filler metal to braze stainless steel heat The biggest problem with the exchanger is that the brazing filler metal contains more melting elements such as B, Si, P, etc., and it is easy to form a variety of eutectics with Fe, Ni, etc., resulting in brittle brazing joints and low strength, only 190MPa ( "Material Engineering" No. 1, 1997, authors Sun Jisheng, Liu Xiaofang

), and the production cost is relatively high

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