Erosion-corrosion of carbon steel in simulated tailing slurries

Research highlights: → Physical model for predicting corrosion-enhanced erosion is established on basis of irreversible thermodynamics. → The model for erosion-enhanced corrosion is modified to consider the non-uniform distribution of anodic dissolution over target surface. → The models are validated by the in-situ microhardness measurement and erosion-corrosion tests. - Abstract: This paper investigates the synergism of mechanical and electrochemical factors in erosion-corrosion. The fact that active corrosion in the tailing slurry donates a small portion of total material loss indicates that the synergism results mainly from corrosion-enhanced erosion. As theoretically predicted, the erosion rates in corroding slurry under same hydrodynamic condition is a linear function of logarithmic corrosion rate, suggesting that the corrosion-induced surface plasticity is the dominate mechanism of corrosion-enhanced erosion. The reduced resistance to plastic deformation in surface layer while exposed to corroding media is demonstrated by the in situ micro-hardness measurements. The erosion-enhanced corrosion in flowing slurry of steel is a result of dynamic plastic deformation caused by erodent impingement.