Anticorrosion surfacing interior joint coating method for submarine pipeline

Abstract

The invention discloses an anticorrosion surfacing interior joint coating method for a submarine pipeline. According to the technical scheme, the method comprises the steps that anticorrosion alloy with a certain width and thickness is surfaced on the inner walls of the two ends of a submarine pipeline steel pipe through an automatic tungsten inert-gas arc surfacing machine, and then anticorrosion and heat preservation treatment are conducted on the inner wall and the outer wall of the steel pipe (the step is shown as the Figure 1); during the submarine pipeline welding construction process, priming and transiting are conducted through argon welding wire filling-free inert gas shielded-arc welding, and by means of a metallurgy composite welding technique of diffusing, filling and covering of flux-cored self-shielded welding wires or manual arc welding electrodes, a continuous anticorrosion layer is formed on the inner wall of the pipeline (the step is shown as the Figure 2).

Description

technical field [0001] The invention relates to the technical field of pipelines, in particular to the field of seabed pipeline anti-corrosion surfacing welding inner joints. Background technique [0002] Submarine pipelines are composed of an inner tube and an outer tube. The inner tube is responsible for transporting media. Generally, crude oil, natural gas, and sewage media are mainly transported. Oil and gas mixed pipelines are also common. Mineralized substances in the media are easy to corrode steel pipes and cause media leakage. It is necessary to carry out anti-corrosion treatment on the inner and outer walls of the steel submarine pipeline to improve its anti-corrosion performance and prolong the service life of the pipeline. [0003] The inner wall anticorrosion of steel pipes for submarine pipelines is generally coated with solvent-based or solvent-free anticorrosive materials in the factory. After the inner and outer walls of the steel pipes are anti-corrosion tr...

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Problems solved by technology

[0006] Chinese Patent Publication No. CN202419038U provides a pipe end liner corrosion-resistant alloy internal anti-corrosion filling technology. The combination of the "lining" layer and the steel pipe base material described in this technology is a mechanical combination, and there is potential corrosion. Using layered welding, no metallurgical composite welding process is involved; Chinese Patent Publication No. CN103008988A provides a joint-free technology of processing grooves on the inner wall of the pipe end and pre-surfacing a layer of stainless steel in the groove, but the inner wall of the base metal The method of processing grooves cannot guarantee the consistency of the mechanical properties of the carbon steel base material; Chinese patent application No. 201510042589.6 and Chinese patent application No. 201510240629.8 both involve surfacing welding technology, but this application does not involve anti-corrosion surfacing welding for submarine pipelines.

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