Full-automatic argon arc welding method of circumferential weld of large-caliber bimetal composite pipe

Abstract

The invention relates to the technical field of a full-automatic welding method of a circumferential weld of a large-caliber bimetal composite pipe, and discloses a full-automatic argon arc welding method of a circumferential weld of a large-caliber bimetal composite pipe. The method includes the following steps of firstly, making a preparation before welding; secondly, conducting root welding, wherein the root welding is conducted through a full-automatic argon tungsten-arc welding machine in the upward direction from the 6 o'clock position to the 12 o'clock position, the protection gas introduced into a welding gun is argon or mixed gas of argon and helium, the volume percentage of the helium in the mixed gas is 15-20%, the purity of the argon is larger than 99.99%, the purity of the argon for welding is not lower than 99.99%, the dew point is not higher than -50 DEG C, and the oxygen content is not larger than 500 ppm. The method has the advantages that root welding is conducted bymeans of the welding gun small-amplitude swinging process, so the back of the weld is well formed, grasping is easy, and defects can hardly appear; and hot welding and filling welding are conducted through U-type swinging adaptive to the groove type, so an electric arc can more easily reach a groove face, and the side wall non-welding problem easily appearing in an existing welding process is eliminated.

Description

technical field [0001] The invention relates to the technical field of an automatic welding method for a large-diameter bimetallic composite pipe girth weld, and relates to a fully automatic argon arc welding method for a large-diameter bimetallic composite pipe circular weld. Background technique [0002] In recent years, bimetallic composite pipes have been used in a huge amount in the oil and gas industry, especially for gathering and transportation pipelines, long-distance pipelines, and process pipelines in high-sulfur, high-chlorine, and high-carbon dioxide oil and gas fields. The use of bimetallic composite pipes in large oil and gas fields such as Tarim Oilfield and Xinjiang Oilfield Company is becoming more and more common, and the pipe diameter has been developed from small and medium diameters to large diameters. [0003] For the welding of large-diameter bimetallic composite pipes, manual inert gas tungsten argon arc welding or argon-electric combination welding ...

AI Technical Summary

Problems solved by technology

[0005] The main purpose of the present invention is to overcome the above-mentioned shortcomings existing in the prior art, and to provide an upward automatic tungsten argon arc welding method for bimetallic composite pipes, which adopts high-frequency wire-feeding vibration technology and narrow gap U-shaped welding method. The combination of groove and its combination solves the problem of full-automatic all-position welding of large-diameter bimetallic composite pipe tungsten argon arc; saves welding materials, greatly improves welding efficiency and welding quality, and greatly reduces production costs and workers labor intensity

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