Alternating Current Corrosion Behavior of X80 Steel in 0.5 mol/L NaCl Solution

The corrosion behavior of X80 steel in solution 0.5 mol/L NaCl solution with alternating current was investigated by polarization curve, electrochemical impedance spectroscopy (EIS), optical microscopy, etc. The results showed that: as AC current density increased, i) the corrosion potentials of X80 in NaCl solution were relatively negative, and the corrosion current densities and values of polarization resistance and impedance modulus fluctuated, while the anodic-to-cathodic Tafel slope radio exhibited drastic changes; ii) X80 steel surface in NaCl solution exhibited more and more large pits and more uniform distribution of small pits, localized corrosion being more serious.