A pipe welding method

Abstract

The invention relates to a pipeline welding method, which specifically includes: a preheating step, when the temperature of the environment where the pipeline is located is lower than zero, preheating the joint to be welded of the pipeline and the surrounding pipe materials to a specified temperature; the welding step, Carry out sealed welding on the joint to be welded along the circumference of the pipe material; heat preservation step, heat preservation treatment is carried out on the weld seam formed in the joint to be welded and its surrounding pipe materials, so that the temperature thereof is not higher than a predetermined The speed decreases until the temperature of the weld and its surrounding pipes drops below a predetermined temperature. The invention controls the temperature of the joint to be welded and its surrounding pipes through the early waste heat and post-insulation, and reduces the residual stress of the joint to be welded and its surrounding pipes, so that the tensile strength of the weld is equivalent to that of the pipe, and solves the problem of low temperature welding Cracks are prone to occur in the end, improve the safe service performance of heating pipes, and protect the work and life of urban residents.

Description

Technical field [0001] The present invention relates to the field of welding techniques, and more particularly to a welding method of a pipe. Background technique [0002] With the continuous development of central heating in northern urban, large thermoelectricons have gradually become one of the main forms of centralized heating. Since the distance between the thermal power plants and the user is generally far, long distance and large-scale supply pipes have gradually become one of the main features of urban centralized heating. Since the winter is short in the north, its work is tight, the amount of construction is large, and the winter construction is inevitably. Arc welding is an important connection method of long-distance heating pipeline. In the cold winter, the weld is often in the first heating season, and the weld will crack, resulting in heating. Pipeline leakage, seriously affecting the work and life of urban residents. Inventive content [0003] In order to solve a...

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Problems solved by technology

[0003] In order to solve all or part of the above problems, the present invention provides a pipe welding method, which controls the temperature of the joint to be welded and its surrounding pipes through the early waste heat and the later heat preservation, and reduces the residual stress of the joint to be welded and its surrounding pipes, so that The tensile strength of the weld is equivalent to that of the pipe, which solves the problem of cracks after low-temperature welding, improves the safe service performance of heating pipes, and ensures the work and life of urban residents

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