Pragukorrosioon

Pragukorrosioon, also known as crevice corrosion, is a localized form of electrochemical corrosion that occurs in confined spaces or crevices where fluid flow is restricted. This type of corrosion typically develops in narrow gaps between surfaces, such as between a bolt and a plate, or within deposits on metal surfaces. The restricted flow within these crevices leads to the formation of stagnant zones, where oxygen depletion occurs, creating a differential aeration cell. This imbalance in oxygen concentration accelerates the corrosion process in the oxygen-depleted area.

Pragukorrosioon is particularly common in marine environments, where seawater can penetrate tight spaces, but it can also occur in other corrosive fluids, including acids, alkalis, and industrial process fluids. The presence of certain ions, such as chlorides, can further exacerbate the corrosion by breaking down protective oxide layers on metals like stainless steel. Materials prone to this type of corrosion include stainless steels, aluminum alloys, and copper-nickel alloys, though the susceptibility varies depending on the specific alloy and environmental conditions.

Preventing pragukorrosioon involves designing systems to minimize crevice formation, using corrosion-resistant materials, and applying protective coatings. Regular maintenance, including inspection and cleaning, can help detect and mitigate early signs of corrosion. In some cases, chemical inhibitors or cathodic protection methods are employed to reduce the severity of the corrosion process. Understanding the environmental conditions and material properties is essential for effective prevention and management of crevice corrosion in industrial applications.