Titanium heat exchange tube welded argon shield device and using method thereof

Abstract

The invention discloses a titanium heat exchange tube welded argon shield device, and belongs to the field of welding machining in mechanical industry. The problem of titanium welding is solved. The device structurally comprises a main body device 1 and an O-shaped rubber sealing ring 3. The main body device 1 is in a pipe shape. One end of the main body device is provided with an air inlet pipe, and the other end of the main body device is closed. The position, close to the air inlet pipe, of the main body device 1 is provided with a large boss and a small boss. The pipe side face is provided with evenly-distributed small holes. The closed end is provided with an annular groove where the O-shaped rubber sealing ring 3 is placed. A using method of the titanium heat exchange tube welded argon shield device comprises the steps that the shield device is placed into a heat exchange pipe 2 to be welded, and the connector part of the air inlet pipe is left outside the heat exchange pipe; the O-shaped rubber sealing ring 3 is tightly attached to the inner wall of the heat exchange pipe 2 to play a sealing role; air inside the heat exchange pipe 2 is cleaned and replaced by argon for a period of time before welding; during welding, argon flows out of the evenly-distributed small holes and flows in the gap between two pipes; after welding, argon is reserved in the pipe for a period of time after a welding gun is turned off, and then the shield device is retreated. The titanium heat exchange tube welded argon shield device is simple in structure and low in cost and ensures production quality.

Description

Technical field [0001] The invention belongs to the field of welding processing in the mechanical industry. Background technique [0002] The chemical properties of titanium are extremely active at high temperatures. It absorbs hydrogen from 250°C, oxygen at 400°C, and nitrogen at 600°C, so titanium is particularly easy to be oxidized during welding. The increase of nitrogen, oxygen and hydrogen will not only increase the weld porosity, but also reduce the plasticity and embrittlement of the weld and heat-affected zone, resulting in welding cracks. At present, argon arc welding under inert gas or vacuum conditions is mostly used. Even if the welding fully meets the process parameters, sometimes the titanium weld will appear golden yellow-purple transition light yellow color or even pores. The effect of gas shielding can be judged from the color of the titanium weld surface. In the process of argon arc welding, the argon protection effect is not good, which will lead to hig...

AI Technical Summary

Problems solved by technology

In the process of argon arc welding, the argon protection effect is not good, which will lead to high temperature oxidation of the weld, hydrogen embrittlement, pores and tungsten inclusions in the weld, resulting in unqualified product quality

Therefore, the protection of the welding heat-affected zone and weld zone of the titanium heat exchange tube at the tube head exceeding 250 °C during welding has become a difficult problem restricting the manufacture of titanium equipment.

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