| Abstract: | Corrosion of unalloyed steel in oxygen-free carbonic acid solution The investigation into the influence of dissolved carbon dioxide on the anodic partial reaction of iron dissolution in 0.5 M sodium sulfate solution has revealed, in agreement with data published in literature, - 1 ) that the transfer of acid molecules to the cathode is the step controlling the rate of cathodic hydrogen evolution in oxygen-free solutions of little dissociated weak acids. The cathodic limiting current density is, consequently, a direct function of acid concentration and not of the pH value as in the case of strong acids.
- 2 ) that the anodic dissolution of iron in sulfate solution is catalyzed by carbonic acid which gives rise to a change of the dissolution mechanism, although this change is not reflected by a change of the cathodic protection potential (?0.85 VCU/CuSo4) which, consequently aplies to waters rich in carbonic acid, too.
|
