Definition and characteristics of pitting corrosion

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This post was last edited by Wang Wei2 on 2026-1-16 at 12:21. Pitting: A type of corrosion in which small holes form in localized areas on the metal surface and penetrate deeper; other areas are either not corroded or only suffer slight corrosion. Features: It is a type of localized corrosion that is highly concealed and highly destructive. It is a corrosion that is accelerated by autocatalysis. Corrosion sites: It occurs mostly on metals and alloys that form a passivation film on their surface, such as SS and Al alloys ； Or on metals with a cathodic coating on the surface, such as Cu, Cr, etc. plated on CS. Erosive halide ions are often present, with the order of activity being Cl ions > Br ions > I ions, and they coexist with oxidizing agents. For a given metal-dielectric system, there exists a specific critical potential.