Abstract

Electrical properties of the interface of 18-8 stainless steel electrode in the passive and transpassive states have been studied by using complex impedance diagrams measured in 1 M-Na2SO4 with pH 2.0 and 6.4.The diagrams obtained in the passive region always showed distorted hemicircles which were equivalent to the impedance loci of electrical circuits having several parallel RC circuits connected in series. It is thought, therefore, that passive films are composed of several layers whose electrical properties are different from one another. Using the resistance at zero frequency (Rω→0) of the diagram and the film thickness which was obtained by ellipsometry, the apparent specific resistance of the passive film was estimated to be ca. 2×1012 Ω·cm.In the transpassive region, the diagrams measured exhibited an inductive loop at extremely low frequencies in addition to a capacitative hemicircle which appeared at high frequencies. The appearance of an inductive loop means that the transpassive dissolution process contains a relaxation process with a large time constant.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.