Crevice Corrosion

This form of attack is generally associated with the presence of small volumes of stagnant solution in occluded interstices, beneath deposits and seals, or in crevices, e.g. at nuts and rivet heads. Deposits of sand, dust, scale and corrosion products can all create zones where the liquid can only be renewed with great difficulty. This is also the case for flexible, porous or fibrous seals (wood, plastic, rubber, cements, asbestos, cloth, etc.).

Potential Adjustment Protection

Normally passive metals when exposed to oxidizing halide environments can suffer from pitting and crevice corrosion. By the application of a direct current the structure potential can be shifted back to the passive region from the transpassive region.

Stainless Steel - Corrosion Resistance: Crevice Corrosion

The corrosion resistance of a stainless steel is dependent on the presence of a protective oxide layer on its surface, but it is possible under certain conditions for this oxide layer to break down, for example in reducing acids, or in some types of combustion where the atmosphere is reducing. Areas where the oxide layer can break down can also sometimes be the result of the way components are designed, for example under gaskets, in sharp re-entrant corners or associated with incomplete weld penetration or overlapping surfaces.