A pre-welding shaping aid and welding method for a large steel cylinder

Abstract

The invention relates to the technical field of forming, assembling and welding of a large-scale supporting cylinder on a lightering platform on the sea, and provides a pre-welding shaping auxiliary mold of the large-scale steel cylinder and a welding method. The shaping mold is composed of a welding platform, a fixing column, a slide way, an outer lead screw, an outer arc locating block, an inner ejector rod and the like. The outer circle of the cylinder is shaped through an adjusted rigid restrained position; shaping accuracy of the cylinder is ensured through the lead screw, a seam width positioning wedge, a process support and the like; a welding process of the cylinder is made; tack welding is firstly conducted on a longitudinal seam, then the longitudinal seam is integrally welded, and the welding sequence is that welding is conducted from the middle towards the two ends at intervals; sectionalized barrel bodies are welded in an assembled mode and through an X-type double-face groove, the butt-jointing groove faces upwards, the inner side of the cylinder is welded firstly when welding is started, carbon arc air gouging back gouging is conducted on a welding seam in the outer side after the cylinder is turned over, and then the outer side of an annular welding seam is welded. Slight welding deformation is achieved through adjustment of a rigidity restraint positioning block and changes of the welding sequence, and requirements for welding accuracy of the cylinder are met.

Description

technical field [0001] The invention belongs to the technical field of welding, in particular to the technical fields of forming, assembling, shaping before welding and welding of a large support cylinder on an offshore barge platform. technical background [0002] The supporting cylinder is the key component of the offshore transfer platform. The circular steel pipe structure must be welded on the main deck. The main bearing is installed on the top of the cylinder by three rows of rollers. Therefore, the cylinder and the main deck must be strictly perpendicular to each other. degree and levelness. The supporting cylinder of the offshore barge platform is welded and assembled by several cylinder sections, and the diameter of the cylinder reaches 2000-4000 mm and the length reaches 6000-15000 mm. Many tools, high labor intensity, long construction period and other problems. [0003] At present, in the production process of such large-scale steel cylindrical parts, after the...

AI Technical Summary

Problems solved by technology

This method has great limitations: first, if the welding site of the cylinder body does not have the post-weld mechanical correction conditions, it is difficult to ensure the roundness and levelness requirements of the cylinder body; The shape correction will have an adverse effect on the performance of the material of the cylinder, and will affect the overall strength of the support, impact resistance, water quality, and environmental pollution of the offshore barge platform.

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