Cathodic Protection Aluminum Alloy Sacrificial Anode for Seawater Pipelines

Cathodic Protection Aluminum Alloy Sacrificial Anode for Seawater Pipelines

Cathodic protection is an electrochemical protection technique used to prevent metal corrosion in electrolytes such as seawater, freshwater, and soil. The fundamental principle of this technology involves applying a certain direct current to the protected metal surface, inducing cathodic polarization. When the metal's potential becomes more negative than a specific threshold, the anodic dissolution process of corrosion is effectively inhibited. Depending on the method of providing the cathodic current, cathodic protection is divided into two types: sacrificial anode method and impressed current method. The former involves electrically connecting a more negatively potential metal (such as magnesium, aluminum, zinc, etc.) to the protected metal structure. Through the continuous dissolution and consumption of the electronegative metal or alloy, a protective current is supplied to the protected object, ensuring the metal structure is safeguarded. The latter converts external alternating current into low-voltage direct current, transmitting the protective current to the protected metal structure via an auxiliary anode, thereby inhibiting corrosion. Whether using the sacrificial anode method or the impressed current method, effective and rational design and application can achieve excellent protection results. Cathodic Protection Aluminum Alloy Sacrificial Anode for Seawater Pipelines
The combined application of cathodic protection and coatings can provide the most economical and effective protection for underground or underwater metal structures. A good coating can protect over 99% of the external surface of a structure from corrosion. Underground or underwater metal structures are typically coated with protective coatings before use to electrically insulate the metal from the electrolyte environment. If the metal structure can be completely electrically insulated, the formation of corrosion cells in the electrolyte will be suppressed, preventing the generation of corrosion currents and thus averting metal corrosion. However, an ideal coating does not exist. Due to transportation, installation, and repair during construction, thermal and soil stresses, coating aging, and the presence of microscopic pinholes, the external coating of metal structures will always have some defects, which ultimately lead to localized corrosion. The combined application of cathodic protection technology and coatings can effectively address this issue. On one hand, cathodic protection can effectively prevent corrosion at coating defects, extending the coating's service life. On the other hand, the coating significantly reduces the required protective current, improves current distribution, increases the protection radius, and makes cathodic protection more economical and effective. For bare or poorly coated underground or underwater metal structures, cathodic protection may even be the only viable corrosion prevention method. The cost of cathodic protection typically accounts for only 1% to 5% of the total cost of the protected metal structure, while the structure's service life can be extended severalfold or even dozens of times. As a result, this technology has gained widespread recognition and is increasingly applied in fields such as ships, port facilities, marine engineering, petrochemicals, power, and municipal engineering, with very promising prospects. Cathodic Protection Aluminum Alloy Sacrificial Anode for Seawater Pipelines

Jiaozuo Libo Light Alloy Co., Ltd. Cathodic Protection Aluminum Alloy Sacrificial Anode for Seawater Pipelines