Crevice corrosion

Crevice corrosion:            In the presence of electrolyte solution, in the narrow gap between metal and metal or between metal and non-metal, the migration of medium is blocked, which is a kind of local corrosion form            Crevice corrosion will reduce the effective geometry size and the degree of fit. The volume of corrosion products in the joint increases, forming local stress and making assembly difficult.            Metal structural parts are generally connected by riveting, welding, screws and other ways, so it is easy to form gaps in the connection parts. The width of the gap is generally 0.025-0.1mm, which is enough to keep the medium in it and cause the corrosion of the metal in the gap. This is called crevice corrosion. Crevice corrosion can occur on all metals and alloys, and passivated metals and alloys are more likely to occur. Crevice corrosion can occur in any medium (acid-base salt), but solution containing Cl - is more likely to occur.