Arc-shaped semi-closed gas protective hood for pipeline welding and welding method

Abstract

The invention relates to an arc semi-closed gas protection cover for welding a pipeline and a welding method. The arc semi-closed gas protection cover comprises an arc shell, an arc pressing ring, a stainless steel silk screen layer, an arc baffle plate, a fixed lug, a buffer layer and an air inlet assembly, wherein the arc baffle plate and the stainless steel silk screen layer are arranged in a clamping groove of the arc shell; the arc pressing ring is arranged on the inner surface of the arc shell; one end of the arc shell is fixedly connected with a welding gun through the fixed lug, and the buffer layer is arranged between the arc shell and the welding gun and used as a transitional layer; the air inlet assembly is arranged on the radial side wall of the arc shell. The arc semi-closed gas protection cover is reasonable in design, simple in structure and easy to operate; a connector seam and a hot influence area can be ensured to stay at a protective state, so that a weld seam with silver-white surface, excellent quality and mechanic property meeting the requirement can be obtained.

Description

technical field [0001] The invention relates to an arc-shaped semi-sealed gas protection drag cover for pipeline welding and a pipeline welding method, which belongs to the technical field of protection devices for automatic welding equipment, and is suitable for gas protection on the surface of weld seams in high-temperature zones during welding of series diameter welded pipelines in various industries. Background technique [0002] Austenitic stainless steel, duplex stainless steel, and nickel-based alloys are mostly used in the nuclear island circuit pipeline materials of nuclear power sites, which have high requirements on weld performance. Open automatic welding orbital heads are often used for welding small-diameter circuit pipelines. During the welding process, only The molten pool area directly below the ceramic nozzle and the weld area in a small range are under gas protection, while the weld seam and heat-affected zone in the high-temperature zone of the welded join...

AI Technical Summary

Problems solved by technology

[0005] 1. The position of the ceramic nozzle clamped by the gas drag cover is unreasonably designed, and the ceramic nozzle is often broken due to excessive pressure during the welding process, which increases the production cost;

[0006] 2. The design of the gas channel is unreasonable, so that the shielding gas distribution in the high temperature zone weld seam and the heat affected zone is uneven, and a good protection effect cannot be achieved, resulting in the blueness of the surface of the welded joint;

[0007] 3. The protective drag cover is directly in rigid contact with the weld seam, which can easily cause pollution of elements such as C and Fe in the weld seam and affect the quality of the weld seam;

[0008] 4. The protective tow cover is separated from the nozzle of the machine head. During automatic welding, the random head cannot be rotated automatically. An additional person is needed to assist in dragging the gas protection tow cover at any time, which increases labor costs.

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