Erosion-enhanced corrosion of carbon steel at passive state

Erosion-enhanced corrosion of carbon steel in passive state during slurry impingement is dominated by the competition between fresh surface generation and repassivation. The presence of chloride retards repassivation. The average corrosion rate is quantitatively predictable when the hydrodynamics of slurry and repassivation kinetics of target material are known. The electrochemical impedance spectroscopy suggests that the corrosion in flowing slurry is under mixed control of interface charge transfer and mass transport. The later becomes the dominative role gradually with increasing generation rate of fresh surface. Slurry impingement may facilitate pit formation and promote repassivation of existing pits simultaneously.

Research highlights► The accelerated corrosion of a passive target is quantitatively predictable after the parameters of slurry hydrodynamics and repassivation kinetics of target in corrosive slurry. ► The corrosion of test material in flowing slurry is likely under the mixed control of interface charge transfer and mass transfer. ► The slurry impingement can promote the nucleation and repassivation of metastable pits simultaneously.