Apparatus and method for monitoring metal corrosion under organic coating

Abstract

The invention relates to a device for monitoring metallic corrosion, in particular to a device for monitoring the metallic corrosion under an organic coat and a monitoring method thereof. The device comprises an electrolytic cell cap, a barrel made from the material same as metallic material to be monitored, a nickel bar and a socket connector. The nickel bar which is equipped with a shielded conductor is connected with the electrolytic cell cap. The internal wall of the barrel is plated with nickel, the external surface is coated with a coat uniformly, then electrolyte is put in the barrel, and the nickel bar is inserted in the barrel. The shielded conductor at the barrel and the nickel bar is led out by the electrolytic cell cap. The led-out shielded conductor is connected with a potentiostat by the socket connector. The inside of the barrel is provided with a corrosion signal monitoring working electrolytic cell. A nickel-plated surface on the internal wall of the barrel is a signal detection working face. The external wall of the barrel and a coat surface on the external wall are corrosion reaction faces. A signal output end of the potentiostat is connected with a data collector and a computer for collecting a monitoring device signal and realizing the monitoring towards the metallic corrosion degree and the corrosion speed under the coat. The invention can monitor the metallic corrosion status under the coat fast and continuously for a long time.

Description

technical field [0001] The invention relates to a monitoring device for metal corrosion, in particular to a device for monitoring metal corrosion under an organic coating and a monitoring method thereof. Background technique [0002] All major developed countries in the world attach great importance to the monitoring of metal material corrosion and environmental corrosion. In the 1980s, the British North Sea Oilfield actively carried out marine corrosion environment measurement, evaluated its corrosion capability and drew a corrosion map. Corrosion monitoring has been widely used on offshore oil platforms in various countries. [0003] With the continuous development of my country's oil and natural gas industry for decades, more and more oil and natural gas production facilities and pipelines have been extensively constructed. The external corrosion protection of these pipelines is generally undertaken by a protection system consisting of coating and cathodic protection. ...

AI Technical Summary

Problems solved by technology

Due to the harsh corrosive environment of the atmosphere, soil, seawater, and sea mud, the transportation pipeline is especially affected by the H caused by industrial production. 2 S, SO 2 , CO 2 And the corrosion of other substances, the surface protective coating will fail or be partially damaged after long-term use, resulting in the exposure of the pipeline substrate to the corrosive medium, resulting in serious corrosion of pipelines and other important production facilities

For example, natural gas produced in some gas fields in western Sichuan contains H 2 S, SO 2 There is less corrosive gas, and the internal corrosion of the pipeline is relatively light. However, because the gas pipeline is buried in the soil, it has been in a harsh corrosive environment for a long time, resulting in the failure, peeling and damage of the external coating of the pipeline, resulting in serious external corrosion of the pipeline.

Once the pipeline is corroded and causes oil and natural gas leakage, it will not only bring huge losses to the oil and gas fields, but also cause environmental pollution and adverse social impacts, which will bring great harm to the safety of people's lives and property

After long-term production and environmental corrosion in some oil and gas field production facilities and pipelines in my country, the integrity of the coating has been destroyed, and the protective effect of some external coatings has been greatly weakened, which has brought great safety to production. Hidden dangers, if not discovered in time and effective measures taken, will cause serious production accidents

However, due to the large number of pipelines and the location in some areas that are difficult to observe with the naked eye, such as soil, seawater and sea mud, it is difficult to monitor the corrosion of steel under the coating.

At the same time, it takes a lot of time and money to rely on manual real-time, on-site inspection and monitoring, and it is impossible to find problems in time.

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