Method of diffusion connection of zirconium and zirconium alloy with stainless steel, including sample processing: processing of Zr 3 to be welded and 316L to be welded surface; Surface cleaning: clean and dry the surface of Zr 3 and 316L to be welded, and clean and dry the intermediate layer material Ti foil; Welding assembly: after cleaning and drying the specimen to be welded Ti foil in the middle, Zr 3 and 316L distribution on both sides, and spot welding fixed around the welding; Furnace loading: the surface of two graphite blocks in contact with Zr 3 and 316L specimens to be welded is coated with solder resistance, and the assembled and spot-welded specimens and graphite blocks to be welded are assembled on the working platform of the vacuum diffusion welding machine; Welding: Keep the specimen to be welded in axial alignment with the upper and lower pressure head of the diffusion welder, apply pressure to the welded specimen, and carry out thermal insulation and pressure preservation three times for diffusion connection. The invention has the advantages of simple process flow, low cost, strong operability and good repeatability.
Zirconium and zirconium alloys are widely used in engineering, energy and chemical industries because of their comprehensive properties such as small neutron absorption cross section, high thermal conductivity, good mechanical properties at high temperature, excellent processing properties and good corrosion resistance. Stainless steel has excellent corrosion resistance, high strength, low cost and excellent processing and welding properties, is one of the most widely used metal materials in engineering. Zirconium and its alloys are often used as functional materials due to their high cost, while low-cost stainless steel is often used for structural support and other relatively favorable service conditions. Therefore, in the engineering, it is inevitable to face a lot of zirconium and zirconium alloy and stainless steel connection problems. In addition, due to the special service conditions of chemical industry, zirconium and zirconium alloy and stainless steel connection structure is usually required to withstand a certain temperature, acid-base medium and even radioactive radiation test.
Diffusion connection is a kind of precise solid-phase connection method. It is a welding method that makes the atoms of the contact surface diffuse each other and achieve metallurgical bonding by holding heat for a certain time under certain temperature and pressure conditions.
In the temperature cycle of the diffusion connection process, the discordant deformation of the dissimilar materials will affect the quality of the diffusion joint due to the difference of the thermal expansion properties of the two materials. In addition, a variety of intermetallic compounds exist in the Zr-Fe binary metal system, such as Fe2Zr, FeZr2, FeZr3, etc. Brittle intermetallic compounds are easy to cause the deterioration of mechanical properties and poor corrosion performance of welded joints.
