The following article discusses “Technical Note: Potential-pH Diagrams for the Fe-CI−-H2O System at 25 to 150°C,” by S. Kesavan, T.A. Mozhi, B.E. Wilde, which was published in Corrosion 45, 3(1989): p. 213. A reply from Kesavan follows.
The following discussion is by P. Paine (EPRI).(2)
I have a few comments concerning the Technical Note in the March 1989 issue, on page 213 by Kesavan et al. The authors would predict that steam generators are filled with hematite (Fe2O3), rather than magnetite (Fe3O4), at operating temperatures above 150°C.
Steam generators operate at about the hydrogen evolution potential at bulk water pHs of 5.5 to 6.0 (at 280°C, 553°K). The oxygen concentration, while very low, is not negligible in a lot of cases. We do not normally operate with saturated NaCI, but in going from Fe to...
