Mass transfer and electrochemical kinetic interactions in localized pitting corrosion

Identification and characterization of coupled diffusional and electrochemical kinetics effects was achieved under potentiostatic anodic dissolution conditions. A one‐dimensional artificial pit geometry with sample wire electrodes embedded in an inert support exposed to NaCl solutions was used to study the dissolution of stainless steel and highnickel Alloy 600. Multiple steady states for both materials were determined at conditions where the diffusional transport rates balanced the electrochemical rate of dissolution at the surface of the wire electrode. A theoretical transport model was developed to quantitatively explain the observed multiple steady state phenomena.