Welding method for boiler drum barrel body

Abstract

The invention discloses a welding method for a boiler drum barrel body. The welding method comprises the steps that the length of a first root face and a second root face is reduced, the distance between the first root face and the second root face is increased, argon arc welding is carried out on a first to-be-welded part and a second to-be-welded part along one side of the first to-be-welded part and one side of the second to-be-welded part, and single-face welding and double-face forming are achieved; manual welding is carried out on the two sides of the first to-be-welded part and the twosides of the second to-be-welded part; and submerged-arc automatic welding is carried out on the two sides of the first to-be-welded part and the two sides of the second to-be-welded part. According to the welding method for the boiler drum barrel body, by reducing the length of the root faces and increasing the distance between the root faces, argon arc welding can achieve single-face welding anddouble-face forming, and carbon arc air gouging, polishing and back gouging are not needed; as a first weld seam of argon arc welding is thin, a second weld seam of manual welding is used for preventing weld penetration of the first weld seam during submerged-arc automatic welding. Single-face argon arc welding, double-face manual welding and double-face submerged-arc automatic welding are carried out sequentially, and therefore the problems that a traditional technology is long in welding time, high-strength steel generates cracks easily, and the cost is high are solved.

Description

technical field [0001] The invention relates to a welding method for a boiler drum body. Background technique [0002] The steam drum (also known as the drum) is the most important pressure component in the boiler, and is the connection hub for the three processes of water heating, evaporation and superheating. It is used to ensure the normal water circulation of the boiler and the quality of the boiler steam, and has a certain heat storage capacity. , moderate the speed of steam pressure change, and ensure the safe operation of the boiler. In recent years, due to the wide application of biomass power generation and the vigorous development of ethylene and other projects, the demand for steam drums has risen sharply. Due to the different working conditions, the material of the steam drum is also changing. The conventional Q345R material is more and more replaced by 13MnNiMoR of low-alloy high-strength steel, and higher-grade materials are also emerging. The wall thickness ...

AI Technical Summary

Problems solved by technology

The wall thickness ranges from more than 10 millimeters to more than 100 millimeters, and the diameter ranges from less than 1 meter to more than 4 meters. However, due to certain technical defects in the existing manufacturing process, it leads to low production efficiency, long manufacturing cycle, and the use of welding materials. Problems such as high manufacturing cost, especially for the manufacture of large-diameter, thick-walled steam drums, the existing technology needs to be optimized and perfected to improve the qualified rate of welds, save welding materials, and reduce labor intensity of workers

However, MT or PT detection needs to be carried out in a cold state, resulting in a long cooling pause time; and because of the large thickness of the steam drum, preheating is required before welding, and re-preheating is required for welding after MT or PT detection. Increased likelihood of weld cracks

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