What occurs during "galvanic corrosion"?

Galvanic corrosion occurs when two dissimilar metals are electrically connected in the presence of an electrolyte, such as water or a corrosive environment. This connection creates a galvanic cell, where one metal acts as an anode and corrodes at a faster rate, while the other metal serves as a cathode and is protected from corrosion. The differences in electrical potential between the two metals drive the corrosion process; the more active metal (anode) will lose electrons and deteriorate, leading to corrosion. This phenomenon is crucial to understand in the context of materials selection and corrosion prevention, as it highlights the importance of considering material compatibility in environments that promote corrosion.

Other options do not accurately represent the mechanism of galvanic corrosion. Electrolysis typically refers to the process of using electricity to drive a chemical reaction, which involves more complex conditions than just two similar metals. Corrosion due to temperature variation relates more to stress corrosion cracking or accelerated rates of corrosion but does not specifically describe galvanic corrosion. Oxidation in freshwater pertains to chemical reactions occurring in a non-corrosive environment, which is not relevant to the galvanic mechanism. Understanding the specific conditions for galvanic corrosion helps prevent severe material degradation in engineering applications.