What causes galvanic corrosion?

Galvanic corrosion occurs when two dissimilar metals are in electrical contact in the presence of an electrolyte, such as water. This phenomenon happens because each metal has a different electrochemical potential, leading to one metal corroding faster than it normally would while the other experiences less corrosion. The less noble metal (the one that corrodes more easily) acts as the anode, while the more noble metal avoids corrosion and acts as the cathode. This process is influenced by the materials involved and their specific position in the galvanic series.

In practical applications, such as water systems, galvanic corrosion can pose a significant risk, particularly when metals like copper and steel are joined. The interaction between these metals leads to accelerated deterioration of the anodic metal, resulting in leaks and structural failures over time. Addressing issues of galvanic corrosion often involves using insulating materials or coatings to separate the dissimilar metals and minimize the potential for corrosion.