A Critical Review of IR Drops and Electrode Potentials within Pits, Crevices and Cracks.
Abstract
The experimental data showing variations in electrode potential in actively growing pits, crevices and cracks are reviewed. Direct potential measurement, proton discharge within the local cell when thermodynamically unfavorable at the outer passive surface, faceting of the pit and crevice walls, and the presence of an active/passive boundary conclusively prove that pitting and crevicing of iron occurs when the electrode potential within the cell is below (less noble than) the Flade or passivation potential of the crevice solution. Low pH and Cl and other aggressive ions, are proposed to increase both the stability and rate of localized corrosion by increasing the size of the active loop and/or magnitude of the passive current of the cavity solution.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA192481
Entities
People
- Howard W. Pickering
Organizations
- Pennsylvania State University