Pressure vessel cylinder longitudinal seam welding device and welding method

Abstract

The present invention discloses a longitudinal seam welding device and method for a pressure vessel cylinder, and relates to the technical field of longitudinal seam welding for pressure vessels. Four pairs of welding guns are provided, and the four pairs of welding guns are enclosed in a rectangle, wherein the welding guns at both ends weld synchronously toward the center of the weld, so that the welding stress is concentrated toward the middle of the weld, and pressure wheels are arranged on both sides of the welding gun, and their rotation directions are all directed toward the weld, promoting the flow of weld fusion material toward the center of the weld. By simultaneously applying internal and external synchronous welding and welding two longitudinal seams from both ends to the center, the heat input and cooling during the welding process are symmetrical in the circumferential direction, and then the transverse shrinkage force and the longitudinal shrinkage force generated by the shrinkage of the weld are equal in size and opposite in direction at the symmetrical position, and their ability to restrain and offset each other is greatly enhanced, so as to reduce the influence of welding stress, and the shear force generated by the rotation of the pressure wheel drives the molten metal to migrate toward the center of the weld, thereby reducing the bite defect.

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