Pit­ting cor­ro­sion

Pitting corrosion describes the form of corrosion that is revealed as punctiform, small holes on a passivated surface. This involves strictly delineated anode areas forming on the surface of the material, whilst the remainder of the surface maintains a cathodic effect. This may occur where a more noble top coat is perforated locally as a result of mechanical damage. The minimal spread across the surface means that this form of corrosion often goes unnoticed.