The influence of chromium on the mass transfer limitation of the anodic dissolution of ferritic steels FeCr in molar sulphuric acid
Résumé
By tracing steady-state, ohmic drop corrected anodic polarization curves, the influence of chromium on the limitation caused by mass transfer onto the anodic dissolution of ferritic steels FeCr containing 10, 12, 17 and 22% of chromium in a molar sulphuric acid medium has been determined. This investigation which was carried out with a rotating disc electrode revealed a partial blockage of the reaction surface from a diffusion standpoint, and the existence of two parallel dissolution processes. Thus, it has been possible to determine the influence of chromium on each of these two processes, only one of which is partially limited by mass transfer, given that the proportion of this latter process in the overall current increases with the chromium concentration of the alloy.