Argon arc welding method suitable for self connection of TiAl-based alloy material

Abstract

The invention discloses an argon arc welding method suitable for self connection of a TiAl-based alloy material. The plasticity of the welded TiAl-based alloy is improved by thermal treatment before welding, so that the welding property of the TiAl-based alloy is improved; and the thermal treatment temperature selected before welding is 1,310 to 1,350 DEG C. The method comprises the following steps of: preparing a Ti-Al-Nb series filling material, wherein the Ti-Al-Nb series filling material contains 40 to 50 percent of Al, 0 to 10 percent of Nb, 0 to 3 percent of V, 0 to 2 percent of Mo, 0 to 4 percent of Cr and the balance of Ti; preheating a welded part by adopting an induction coil at the temperature of between 500 and 800 DEG C, wherein the preheating and welding operations are finished in an argon filled box in order to avoid the problems of oxidation and hydrogen absorbing embrittlement of the TiAl-based alloy and the like; and after the welding is finished, performing annealing and stress removal treatment on the welded piece, wherein the annealing temperature is 900 DEG C. Compared with the methods of electron beam welding, laser welding and the like, the welding method provided by the invention is simple and convenient in operation, low in cost and convenient for popularization, can be used for repair welding of defects of castings or forgings of the TiAl-based alloy, and is suitable for efficient self connection of the TiAl-based alloy.

Description

technical field [0001] The invention belongs to the field of welding technology and relates to an argon arc welding method suitable for self-connection of TiAl-based alloy materials. Background technique [0002] The density of TiAl intermetallic compound alloy is only 3.8-4.0g / cm 3 , is 1 / 2 of the nickel-based superalloy, 10% lower than the titanium alloy; its elastic modulus at room temperature is as high as 160-170GPa, 30% higher than that of the titanium alloy, and the elastic modulus can maintain 150GPa at a high temperature of 750°C, which is comparable to that of the titanium alloy. GH4169 high-temperature alloy is equivalent; TiAl-based alloy also has high specific strength, the strength retention rate at room temperature -800°C reaches 80%, high creep resistance, excellent oxidation resistance and flame retardancy, and can work for a long time at 760°C-800°C. Very promising lightweight high temperature resistant structural material. From the end of the 1980s to th...

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Problems solved by technology

There is no relevant report on the filler materials used in arc welding of TiAl-based alloys.

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