ELECTROCHEMICAL STUDIES OF ANODIC-DISSOLUTION OF MILD-STEEL IN A CARBONATE-BICARBONATE BUFFER UNDER EROSION-CORROSION CONDITIONS

A Rotating Cylinder Electrode (RCE) system has been used to determine the corrosion kinetics of mild steel in the active dissolution potenti al range under erosion-corrosion conditions. The hydrodynamics of the rotating cylinder electrode were characterized by the mass transfer co ntrolled oxygen reduction reaction on a copper electrode. The anodic d issolution current was measured at various potentials and velocities i n de-aerated 0.5M NaHCO3 + 0.5M Na2CO3 solution, with or without the a ddition of 300 g/l of 100 mu m alumina. The results show that anodic d issolution processes in this system are under mass transfer control in turbulent flow conditions. The anodic dissolution rate increases sign ificantly with the introduction of particles, owing to an increase of mass transfer coefficient and removal of corrosion deposits on the ele ctrode surface. Copyright (C) 1996 Elsevier Science Ltd.