Reverse bottoming welding method for large-diameter stainless steel molten salt pipeline

Abstract

The invention discloses a reverse bottoming welding method for a large-diameter stainless steel molten salt pipeline, and mainly relates to the field of large-diameter pipeline welding. The method comprises the following steps that S1, a first welding pipeline and a second welding pipeline are prepared; S2, beveling is carried out; S3, assembling is carried out to form a welded junction; S4, a worker enters the pipeline for welding preparation; S5, the worker outside the pipeline starts argon, and holds an argon filling nozzle to be aligned with the welding position of arcing; and S6, after external argon filling is started, the welding worker is aligned with the argon filling position to start arcing, along with movement of an electric arc, the argon filling worker holds the argon filling nozzle and enables the argon filling nozzle to synchronously move along with the electric arc, and the argon filling effect is guaranteed. The method has the beneficial effects that the bottoming quality of the welded junction can be checked at any time, defects are eliminated in time, argon filling protection is carried out outside the pipeline, the argon supply flow can be reduced, meanwhile, waste caused by argon loss in the argon filling process is avoided, the air chamber manufacturing link is omitted, a large amount of time, consumables and labor cost are saved, and the construction efficiency and economic benefits are improved.

Description

technical field [0001] The invention relates to the field of large-diameter pipeline welding, in particular to a reverse bottoming welding method for large-diameter stainless steel molten salt pipelines. Background technique [0002] During the construction of CSP power plants, there are a large number of large-diameter stainless steel molten salt pipes, and their welding quality and construction efficiency will directly affect the safe and stable operation of the entire unit and the progress of the construction period. Improper selection of process methods will also increase consumables and reduce construction benefits. [0003] At present, the bottom welding of large-diameter stainless steel molten salt pipelines on the construction site mostly adopts argon tungsten arc welding for external bottoming and internal argon protection. The protective gas chamber is mostly made of high-density sponge, water-soluble paper, etc., which are arranged within 10cm-20cm on both sides ...

AI Technical Summary

Problems solved by technology

[0004] The quality of the weld joint cannot be checked at any time during the front-side rooting welding process of the above-mentioned prior art, and defects such as incomplete fusion and incomplete penetration of the root cannot be found in time, resulting in quality hazards; according to different specifications of pipes, it is necessary to manufacture a variety of different specifications The high-density sponge and water-soluble paper air chamber, the production process is more complicated, time-consuming and laborious, and the air chamber is easily damaged by heat, which will increase the cost of consumables and labor, and reduce economic benefits; the air chamber needs to be completely replaced during the argon filling process, and it is easy Argon gas is wasted due to poor sealing of the air chamber, which increases consumables and reduces economic benefits

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