A method for pre-filling welded joints of steel pipes

Abstract

The invention discloses a pre-joint coating method for a welded junction of a steel pipe. The method comprises: penetrating a stainless steel short pipe into the steel pipe from an end part of the welded junction so as to enable both a first end and a second end of the stainless steel short pipe to be located in the steel pipe; adopting a welding gun to perform rotary build-up-welding on the inner wall of the steel pipe along the direction away from the short pipe from the first end so as to form a first build-up-welding layer; adopting the welding gun to sequentially perform solution treatment on the first build-up-welding layer and the stainless steel short pipe from a first end point to the second end so as to form point potential gradual transition from low-carbon alloy to stainless steel and to enable a contact surface of the first build-up-welding layer and the short pipe to be in slope-shaped transition; and adopting the welding gun to perform build-up-welding on the inner wall of the steel pipe from the second end to the end part of the welded junction to form a second build-up-welding layer. By means of the method, the technical problem existing the prior art that the difficulty of the anti-corrosion repairing operation in the steel pipe is high is solved, and the technical effect of reducing safety and environmental protection risks caused by corrosion and leakage of pipelines is realized.

Description

technical field [0001] The invention relates to the technical field of pipeline technology, in particular to a method for pre-filling welded joints of steel pipes. Background technique [0002] Steel pipeline welds are the weakest link in corrosion resistance. In all pipeline corrosion leakage accidents, pipeline weld corrosion accounts for more than 60%. In order to prolong the service life of pipelines, in the construction of internal anti-corrosion pipelines, it is necessary Carry out anti-corrosion treatment, this process is called "pipeline internal repair"; [0003] The inner joint of the pipeline is generally realized by the joint joint robot. It is necessary to clean the inner wall of the pipeline welding joint first, and then spray the liquid anti-corrosion coating to make the anti-corrosion layer in the pipeline continuous; Internal filling cannot be realized; [0004] For small-diameter pipes, the method of on-site paint extrusion is generally used for internal ...

AI Technical Summary

Problems solved by technology

[0006] The present invention solves the technical problem of high difficulty in the internal anti-corrosion repairing of steel pipes existing in the prior art by providing a method for pre-filling welded joints of steel pipes

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