Mössbauer spectroscopy and electrochemical measurements were used to study the passivation of iron and steels in a sulphite containing solution. The potentiodynamic curves show that passivation occurs at -140 mV potential vs saturated calomel electrode (sce). The main phase of the passive layer was found to be γ-FeOOH, while FeSO4·H2O on the surface and FeSO3·3H2O inside the layer were identified as minor phases in the case of polarization in a solution of pH 3.37. Only γ-FeOOH was observed on the surface of samples polarized at pH 6.6.
ASJC Scopus subject areas
- Chemical Engineering(all)