Method for welding single-arc double-wire pipelines

Abstract

The invention discloses a method for welding single-arc double-wire pipelines, and belongs to the technical field of welding of oil and gas pipelines. The method comprises the following steps of: processing grooves at pipe ends of two pipelines to be welded respectively, and butting the grooves of the two pipelines through a butting function of an internal welding machine; setting welding working parameters of the internal welding machine and an all-position automatic welding machine for the single-arc double-wire pipelines; preheating pipe orifices to be welded to over 50 DEG C, performing root welding on the pipe orifices to be welded by using the internal welding machine; performing hot welding, filling welding and cosmetic welding from inside to outside on the pipe orifices subjected to the root welding by using the all-position automatic welding machine for the single-arc double-wire pipelines until the circumferential surface of a welding seam is not lower than the surfaces of the outer walls of the pipelines; and performing filling welding on a plurality of layers, wherein the filling welding height of each layer is not less than 4 mm. By the method for welding the single-arc double-wire pipelines, the welding efficiency of large-caliber thick-wall pipelines can be effectively increased, and the method has the advantages of high welding deposition efficiency, high welding speed, small heat input, stable heat affected zone and high welding seam mechanical properties.

Description

technical field [0001] The invention relates to the technical field of oil and gas pipeline welding, in particular to a single-arc double-wire pipeline welding method. Background technique [0002] With the continuous development of long-distance oil and gas pipelines with large diameter and large wall thickness and the increasing pursuit of construction efficiency, the industry's demand for high-efficiency welding technology is becoming more and more urgent. In order to improve the efficiency of pipeline construction, various forms of automatic welding machines and welding techniques have sprung up. Although these welding techniques have greatly improved the welding speed, it is difficult to make a breakthrough in the thickness of the weld layer, resulting in a decrease in welding efficiency. The room for improvement is quite limited. Therefore, how to fundamentally improve the welding efficiency of pipelines has become a technical problem to be solved urgently in pipeline...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problems of low welding efficiency caused by the limitation of weld layer thickness in the existing large-diameter thick-walled pipeline welding process, the present invention provides a single-arc double-wire pipeline welding method, which includes: The pipe ends are grooved respectively, and the grooves of the two pipes are aligned through the matching function of the internal welding machine; the welding parameters of the internal welding machine and the single-arc double-wire pipeline full-position automatic welding machine are set; the pipe to be welded Preheat to above 50°C, use the internal welding machine to perform root welding on the nozzle to be welded; use the single-arc double-wire pipeline all-position automatic welding machine to perform heat welding and welding on the nozzle after root welding from the inside to the outside Filling welding and cover welding, until the circumferential surface of the weld is not lower than the outer wall surface of the pipe; the filling welding has multiple layers, and the filling welding height of each layer is not less than 4mm

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