Rapid assembly welding method for large diameter steel pipeline

Abstract

The invention discloses a rapid assembly welding method for a large diameter steel pipeline. The method comprises the steps that a circular butt joint device is manufactured; positioning support plates are evenly distributed at the mouth of a lower steel pipe to be welded, the butt joint device is placed on the support plates, and the butt joint device fastens the lower steel pipe after buckling;an upper steel pipe is aligned with the lower steel pipe for butt joint correction and pre-assembly; two sections of pre-assembled steel pipes are hoisted and placed on rotating bed-jigs horizontally;a submerged arc welding trolley is placed directly above the welding line of the two sections of steel pipes to be welded, and the travel direction of the trolley is consistent with the welding line;the linear speed of a large diameter steel pipeline is the same as the submerged arc welding trolley, and the rotation direction is opposite; after the entire welding line of the steel pipeline to bewelded is finished, the soldering flux residue is removed, and if welding defects are found, manual repair welding and polishing are processed. According to the rapid assembly welding method for thelarge diameter steel pipeline, horizontal welding, vertical welding and overhead welding can be converted into flat welding, and welding process is completed continuously, smoothly and fully-automatically.

Description

technical field [0001] The invention relates to the technical field of welding of steel pipes, in particular to a fast assembly and welding method for large-diameter steel pipes. Background technique [0002] Various welding techniques are available for large diameter pipe welding. In practical application, the appropriate welding technology should be selected according to the actual situation of the project. On the basis of selecting the appropriate welding technology, set the welding process parameters to ensure the welding quality. [0003] The manual welding process has been developed for a long time, and arc welding is mainly used for welding, which can weld large-diameter pipes. Because manual welding has the characteristics of convenient construction and good adaptability, it is a good supplement to large-diameter welding. However, the efficiency of manual welding is low, and there are horizontal welding, vertical welding, and overhead welding, which makes welding ...

AI Technical Summary

Problems solved by technology

However, the efficiency of manual welding is low, and there are horizontal welding, vertical welding, and overhead welding, which makes welding difficult and difficult to guarantee welding quality

[0004] At present, in large-scale steel structure processing and manufacturing enterprises, the conventional welding method for large-diameter steel pipes is to place the pre-assembled large-diameter pipes on the self-made controlled rotating tire frame 3, and fix the welding machine on the welding platform directly above the pipes. The pipe is controlled to rotate with the tire frame, the pipe rotates once, and the entire weld seam is welded. However, due to the influence of its own gravity and pre-assembly residual stress and other factors, the large-diameter pipe with a diameter of 3-5 meters is not normal after the pre-assembly is completed. Round shape, the distance between the welding seam position and the submerged arc welding contact tip is not controlled, if the distance is too close, the current is too large, the weld seam burns through, and the weld seam fails to penetrate if the distance is too large, resulting in many weld seam defects. Rework, time-consuming and labor-intensive, low welding efficiency, and difficult to meet the specification requirements for welding quality

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