Probing the initiation and propagation processes of flow accelerated corrosion and erosion corrosion under simulated turbulent flow conditions

The initiation and propagation of flow accelerated corrosion (FAC) and erosion corrosion (EC) have been explored using an electrochemically integrated multi-electrode array and electrochemical impedance spectroscopy. Results show that the propagation of FAC is due to flow generated interfacial anolyte transportation and micro turbulences around the initial pits, causing the "flow mark" corrosion appearance. While the propagation of EC appears to be mainly due to the impingement of the initial anodic sites by sand particles, inducing the 'crater like' corrosion feature. Mechanical erosion was found to concentrate on electrochemical corrosion anodes, confirming active interactions between erosion and corrosion processes.