Contribution to the Electrochemical Behavior of Chromium and Iron-Chromium Alloys in the Transpassive Region

Abstract

The polarization curves of Cr in electrolytic solutions containing different anions showed that these anions did not have any influence on the mechanism of dissolution of Cr in the transpassive region and that only OH⁻ ions take part. The current/potential curves of and demonstrated the possibility of the former compound being present in the passive layer. Measurements of the roughness factor of Cr after polarization in the active or the passive state indicated that the roughness of the surface remains constant within the accuracy of this method. The average roughness factor was 1.7. Further surface measurements were carried out on a Fe‐Cr alloy (containing 27% Cr) which demonstrated an increase in the roughness of the surface after polarization of the alloy in the primary transpassive region.