The consequences of pitting corrosion depend on how many pits form and how deep they are. They range from a purely cosmetic effect to the structural failure of a load-bearing part.
Shallow pitting
A light distribution of shallow pits may only affect appearance, and the corrosion deposits that form can limit or stop further attack at those points. Even so, shallow pits can be a problem in some applications, such as food production or pharmaceuticals, where contamination from corrosion products or uncleaned areas would harm product quality or safety.
Large or deep pitting
Large or deep pits are far more serious, particularly in load-bearing components. They reduce the effective thickness of the part to unsafe levels and, in extreme conditions, can act as stress concentrators. Failure can then initiate at these points, with structural elements collapsing or pressurised containers exploding.