Crevice corrosion

Crevice corrosion, also known as pitting corrosion or crevice corrosion, is a special form of corrosion that occurs in narrow crevices or crevice areas where access to the environment is limited. This corrosion process often occurs in metallic materials, especially those that are passivating, such as stainless steels, aluminum alloys and titanium alloys.

Crevice corrosion occurs when moisture, oxygen and corrosive substances are trapped and accumulate in narrow crevices or crevice areas. These conditions cause the crevice area to have a different chemical composition than the surrounding surface of the material, leading to localized electrochemical reactions.

A local anode can form in a gap area where the corrosion of the metal takes place, while a cathodic reaction occurs at the neighboring areas, which supports the flow of electrons to the anode. This difference in the electrochemical reactions leads to an accelerated corrosion process in the gap areas compared to the surrounding surface.

Crevice corrosion can cause serious damage as it can lead to deep pitting which can affect the structural integrity of the material. Especially in industrial applications where components are exposed to high loads and aggressive environmental conditions, crevice corrosion can lead to serious failures if not detected and treated in time.

To prevent crevice corrosion, it is important to design components and structures in such a way that crevice areas are avoided or minimized. In addition, appropriate material selection, surface coatings and corrosion protection measures can help to reduce the risk of crevice corrosion. Regular inspection and maintenance is also crucial to identify and treat potential crevice corrosion sites at an early stage before serious damage can occur.