Sacrificial corrosion

Corrosion is a natural process in which metallic materials are degraded by chemical or electrochemical reactions with their environment. Sacrificial corrosion, also known as galvanic corrosion, occurs when two dissimilar metallic materials are in electrical contact and are surrounded by an electrolytic medium.

In such a system, one metal will sacrifice or corrode to protect the other. This occurs through the formation of galvanic cells in which the corroding metal (sacrificial metal) becomes the anode pole, while the protected metal (base metal) is the cathode pole. The flow of electrons between the anode and cathode breaks down the sacrificial metal, protecting the base metal from corrosion.

Sacrificial anodes, often made of zinc or magnesium, are often used in structures prone to corrosion, such as marine or offshore platforms. These sacrificial anodes are designed to corrode faster than the protected metal and must be replaced regularly to maintain effective corrosion protection.

Sacrificial corrosion is an effective method of extending the life of metallic structures and maintaining their integrity. Through targeted sacrificial corrosion, the damaging corrosion is directed to the sacrificial metal while the main material remains protected.