With the development of society and the progress of science and technology, the underwater anti-corrosion technology of steel pipe piles has attracted more and more attention. This article will introduce the relevant knowledge and technology of underwater anti-corrosion of steel pipe piles, including the corrosion mechanism, anti-corrosion measures, underwater anti-corrosion coating and cathodic protection of steel pipe piles.
1. Corrosion mechanism of steel pipe piles.
The corrosion of steel pipe piles is mainly caused by electrochemical corrosion and microbial corrosion. In the marine environment, steel pipe piles will be eroded by a large number of corrosive ions such as chloride ions and sulfate ions, and will also be affected by marine microorganisms, resulting in corrosion.
2. Anti-corrosion measures for steel pipe piles.
1.Surface treatment.
Before the underwater anti-corrosion coating of steel pipe piles, the surface must be treated, including rust removal and decontamination. Rust removal can be done by sandblasting, pickling and other methods, and decontamination can be done by mechanical cleaning, chemical cleaning and other methods.
2.Underwater anti-corrosion coating.
Underwater anti-corrosion coating is an important measure to prevent corrosion of steel pipe piles. Commonly used underwater anticorrosive coatings include epoxy coatings, polyurethane coatings, acrylic coatings, etc. These coatings have excellent weather, water and corrosion resistance, and can effectively protect steel pipe piles.
3.Cathodic protection.
Cathodic protection is an important means to prevent corrosion of steel pipe piles. By applying a cathode current to the steel pipe pile, it becomes a cathode, thereby inhibiting the occurrence of corrosion. Commonly used cathodic protection methods include the impressed current method and the sacrificial anode method.
3. Performance requirements for underwater anticorrosive coatings.
The underwater anti-corrosion coating must meet the following performance requirements:
1.Good water resistance and weather resistance, able to be used for a long time in the marine environment;
2.Good adhesion and abrasion resistance, not easy to fall off and wear;
3.Good electrical insulation, prevent the occurrence of galvanic corrosion;
4.Good resistance to microbial corrosion, able to resist microbial erosion in the marine environment.
Fourth, the effect and influencing factors of cathodic protection.
Cathodic protection can effectively inhibit the corrosion of steel pipe piles, and its effect is affected by many factors. Among them, the influencing factors include current density, current distribution, soil resistivity, etc. In order to improve the effectiveness of cathodic protection, it is necessary to select the appropriate current density and distribution mode, while considering factors such as soil resistivity.
V. Conclusions and recommendations.
Underwater anti-corrosion of steel pipe piles is a very important part of marine engineering. In order to effectively prevent the corrosion of steel pipe piles, a series of anti-corrosion measures need to be taken, including surface treatment, underwater anti-corrosion coating and cathodic protection. In practical application, it is necessary to select appropriate anti-corrosion measures and technologies according to the specific situation to improve the service life and safety of steel pipe piles. At the same time, for other equipment and structures in marine engineering, corresponding anti-corrosion measures and technologies also need to be taken to ensure the safety and reliability of the entire project.