Which type of corrosion occurs when dissimilar metals are in contact in the presence of an electrolyte?

Galvanic corrosion occurs when two dissimilar metals are electrically connected in the presence of an electrolyte, such as saltwater. This type of corrosion is driven by the electrochemical potential difference between the two metals. When they come into contact, one metal (the anode) will corrode preferentially, while the other metal (the cathode) is protected from corrosion.

In a marine environment, where water often contains salts and other ions, the likelihood of galvanic corrosion increases significantly. For example, if a copper component is electrically connected to aluminum in a marine setting, the aluminum can become the anode that corrodes faster due to its higher reactivity compared to copper.

This phenomenon is critical to understand for the protection and maintenance of marine vessels and structures, as preventing contact between dissimilar metals or implementing isolation strategies can effectively mitigate the risk of galvanic corrosion.