Study of cavitation corrosion behaviors and mechanism of carbon steel in neutral sodium chloride aqueous solution

The electrochemical behavior and mechanisms of carbon steel cavitation corrosion in neutral sodium chloride (NaCl) aqueous solution were studied by means of the cavitation corrosion apparatus, using the methods of weight loss, electrochemistry, and the observation of scanning electron microscopy (SEM). The results show that the cavitation corrosion behavior of carbon steel is significantly different under the different liquid media solutions, such as its salt concentration, temperature, testing time, etc., and the corrosive factor of the tested brine has a significant effect on the cavitation corrosion. It was found by measured polarization curves that the cavitation corrosion reaction of carbon steel is mainly controlled by the dissolved oxygen diffusion process in the part of cathode of corrosion reaction, and cavitation erosion promotes the proceeding of the electrode reaction rate of carbon steel. By applying cathodic current, carbon steel cavitation. corrosion velocities drop sharply. This shows that the electrochemical corrosion factor plays an important role in cavitation corrosion, and the synergism effect between electrochemical corrosion and cavitation results in heavy cavitation corrosion of materials.