Welding equipment and use method thereof

Abstract

The invention relates to the field of welding, in particular to welding equipment of a nuclear power station main loop, and a use method of the welding equipment. In order to solve the welding quality problem and the problem of high cost, the welding equipment is provided and comprises two welding torches: a flat welding torch and a standard welding torch; when a deep part of a welding seam is welded, the flat welding torch is used for welding, and when a shallow part of the welding seam is welded, the standard welding is used for welding; the flat welding torch comprises an insulating case, a welding torch base body, a middle insulator, a lower gun body and an electrode assembly which sequentially penetrates through the components, and a channel for cooling water circulation and a channel through which a protective gas can pass are arranged inside the welding torch basal body and the middle insulator and the upper part of the lower gun body; and the lower gun body is in a hollow flat shape except a connecting part of the lower gun body, and an insulating pipe through which an electrode can pass, and a gas strainer capable of allowing the protective gas to be advected are arranged inside the flat structure. The welding equipment both improves the welding quality and saves the cost.

Description

technical field [0001] The invention relates to the field of welding, in particular to welding equipment for automatic welding of narrow gaps in the main circuit of a nuclear power plant and a method for using the same. Background technique [0002] Narrow-gap automatic welding of the main circuit of nuclear power plants is a key technology in the installation and construction of nuclear power plants. The wall thickness of this welded pipe is usually between 60 and 100mm, and the weld seam is usually between 6 and 10mm due to the shrinkage during the welding process. In view of moderate heat input during welding, high welding efficiency, and suitable for all-position welding, narrow-gap automatic welding has been vigorously promoted and applied during the installation and construction of nuclear power plants. [0003] However, there are some technical difficulties in the existing narrow-gap automatic welding of the main circuit of nuclear power plants. For example, the adj...

AI Technical Summary

Problems solved by technology

The disadvantages of this welding torch are: 1. In order to play a protective effect, the flat welding torch is generally made longer in the circumferential direction, so it is inconvenient to observe the molten pool during the welding process, which is not conducive to the adjustment of the operator; 2. . Due to the need to go deep into the weld seam, the height of the flat welding torch is generally relatively large, about 70-80mm, but when it is welded to the surface of the weld seam, the space required is relatively large, which is not conducive to the implementation of welding at the nuclear power site; 3. The welding torch must be cooled by water cooling, but the water cooling method often divides the protection of the tungsten electrode into two parts, the gas circuit is relatively complicated

During the whole welding process, the gas mask needs to be replaced at least three times, which is very tedious

In addition, in addition to replacing the gas cover, the electrode holder with the electrode must also be replaced every time. The electrode holder is an assembly composed of a housing, a connection knob and an electrode fastener, so the replacement is also quite complicated.

[0008] In addition, the welding equipment developed by the French company FRAMATOME did not give a specific solution to the cooling problem of the lower gun body of the flat welding torch.

[0009] In view of the fact that the main circuit of the nuclear power plant has high requirements on welding quality, and the three welding equipment or welding methods described above will bring many problems to the welding quality, it is necessary to develop a new welding equipment to improve the welding quality

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