Electrochemical Corrosion Behavior of 1Cr12Ni3Mo2VN Stainless Steel

To investigate the effects of anodic polarization on the corrosion behavior and re-passivation behavior of martensitic stainless steel in a chloride ion environment， electrochemical testing methods including cyclic polarization， constant potential polarization， and electrochemical impedance spectroscopy (EIS) were employed.Additionally， the influence of anodic polarization potential on the corrosion resistance of 1Cr12Ni3Mo2VN stainless steel was studied using confocal laser scanning microscope (CLSM)， scanning electron microscope (SEM)， energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS).The study analyzed the behavior processes of pitting and re-passivation of the material， as well as the relationship between corrosion resistance and the composition of the passivation film.Results showed that no pitting corrosion was observed on the surface after polarization at a low potential in the passivation zone.The content of Cr2O3 and Fe2O3 in the passivation film was found to increase， while the content of hydroxides decreased， which enhanced the stability of the passivation film and improved the material's corrosion resistance.When the passivation area was polarized at a high potential， an inductive arc appeared in the lowfrequency region of the electrochemical impedance spectrum， and a stable pitting corrosion was formed on the material's surface.The pitting holes were semi-ellipsoidal， and the content of Cr and Mo in the surface layer of the pitting holes increased，while the content of Fe and Ni decreased.After the mixed potential dropped to the protection potential， re-passivation occurred.The repaired passivation film was thinner， the impedance value decreased， and the pitting sensitivity increased.