Effects of particle velocity and applied potential on erosion of mild steel in carbonate/bicarbonate slurry

The present paper describes a study of the combined effects of velocity and applied electrochemical potential on the erosion of mild steel in an aqueous carbonate/bicarbonate slurry. The erodent used was alumina; the velocity was varied between 2 and 10 m s(-1) and the potential between -1.0 and 0.2 V (saturated calomel electrode). Measurements were made of the erosion rate in the absence of corrosion (when the surfaces were cathodically protected), the instantaneous corrosion rate, and the overall erosion-corrosion rate. The results showed that the effect of velocity varied as a function of the applied potential. Velocity exponents were evaluated for the various erosion-corrosion conditions, and the tends in the variation of the exponents were discussed for each of the applied potentials. Criteria for the existence of erosion-corrosion regimes in aqueous environments were suggested, and were used to generate an erosion-corrosion map based on the experimental data. (C) 1996 The Institute of Materials.