What is typically a sign of galvanic corrosion?

Localized pitting or etching is a characteristic sign of galvanic corrosion because this type of corrosion occurs when two dissimilar metals are in electrical contact with each other in the presence of an electrolyte. The more anodic metal tends to corrode preferentially, leading to concentrated areas of material loss.

In galvanic corrosion, the corrosion is not evenly distributed across the surface; instead, it often manifests as small pits or etch marks where the anodic metal is deteriorating more rapidly. This contrasts with uniform corrosion, which affects the entire surface evenly. The other options represent forms of corrosion or deterioration that do not specifically correlate with the mechanisms that define galvanic corrosion. For instance, rust formation typically involves metal surfaces, while the peeling of coatings generally pertains to issues related to adhesion and environmental factors rather than electrochemical reactions between dissimilar metals.