Research on pipeline anti-corrosion coating

Corrosion is the main cause of material failure, and metal corrosion is a major economic problem. According to relevant data statistics, the annual losses caused by metal corrosion in China account for about 5% of the national economy, with pipeline corrosion accounting for a considerable proportion. With the sustained and rapid development of China's economy, the demand for energy is constantly increasing, and the amount of pipeline construction is also increasing. Various gas supply, water supply, and heating pipelines that will be built in various city plans are also countless. This makes the protection of pipeline corrosion increasingly important, which directly affects the anti-corrosion performance and operating life of pipelines. Therefore, strengthening the research on pipeline anti-corrosion coatings is of great significance for the corrosion control of the entire pipeline.
2、 Current research status of pipeline anti-corrosion coatings
2.1 Reasons for pipeline corrosion
Corrosion refers to the chemical and electrochemical reactions that occur on the surface of metal materials and environmental media, causing material degradation and damage. The common corrosion of oil pipes is mainly caused by corrosive substances such as CO2, H2S, C1-, small amounts of dissolved oxygen, and bacteria dissolved in crude oil. These substances directly interact with metals, causing chemical corrosion.
The harm of chemical corrosion is not significant, and the main reason for the appearance of protrusions and even perforation on the surface of steel pipes comes from electrochemical corrosion. When metal undergoes electrochemical reactions, the areas with lower electrode potentials are prone to losing electrons and becoming anodes; The area with higher electrode potential receives electrons and becomes the cathode. In the presence of O2 and H20, Fe (OH) 2 generates hydrated iron oxide, which leads to corrosion.
2.2 Function and performance requirements of anti-corrosion coatings
1. The role of anti-corrosion coatings
The main principle of anti-corrosion coating is to prevent corrosive media such as H2O, Cl -, SO2 from penetrating the metal surface in the environment, isolating the corrosive media from the metal surface and preventing metal corrosion. The main functions of pipeline anti-corrosion coating are as follows:
1) Shielding effect. 2) Corrosion inhibition performance. 3) Sacrificial anode protection. 4) Performance improvement effect.
2. Performance requirements for pipeline anti-corrosion coatings
In order to improve the anti-corrosion performance of coatings and maximize their anti-corrosion effect, combined with the actual situation of pipeline anti-corrosion, the requirements for the performance of anti-corrosion coatings are as follows: 1) Good stability of corrosive media. 2) Good impermeability, ensuring low water absorption. 3) Has good mechanical strength. 4) Has excellent electrical insulation properties.