Crevice corrosion is a localized form of corrosion, under the influence of "crevice geometries". Well-known examples of such geometries include flanges, gaskets, disbonded linings/coatings, fasteners, lap joints and surface deposits. Stagnant solution plays an important role in setting up of highly corrosive micro-environments inside such crevices. A metallic material tends to assume a more anodic character in the stagnant crevice solution compared with the bulk surface (exposed to the bulk environment).

As in pitting attack, systems relying on passive surface films for corrosion resistance can be particularly vulnerable to this mode of corrosion. The highly corrosive micro-environment of crevices tends to be similar to the micro-environment established at the base of corrosion pits. Crevice corrosion is associated with induction (initiation) and propagation phases.

A more recent approach has been to incorporate micro-sensors inside the corrosive micro-environments of crevice geometries. The use of fiber optic sensors and micro-electrodes has been introduced for these purposes.

Most corrosion scientists and engineers are all too familiar with unwanted crevice effects occurring on corrosion probes that are designed to monitor other forms of corrosion damage. The interface between the sensor element and the probe body can be particularly prone to undesirable crevice attack, resulting in extraneous corrosion signals. This frustrating problem can also occur where electronic leads are attached to certain corrosion sensors.