6533b86dfe1ef96bd12c9ea0

RESEARCH PRODUCT

A study of electrochemically-induced corrosion of low carbon steel in a medium modelling acid rain

Philipp GütlichA. VértesM. Lakatos-varsányiCs. VértesW. Meisel

subject

Nuclear and High Energy PhysicsAqueous solutionCarbon steelPassivationInorganic chemistryengineering.materialCondensed Matter PhysicsElectrochemistryAtomic and Molecular Physics and OpticsCorrosionchemistry.chemical_compoundSulfitechemistryengineeringPitting corrosionPhysical and Theoretical ChemistrySulfate

description

Complementary electrochemical, spectrophotometric and electron microsopic investigations were made in addition to the conversion electron Mossbauer spectroscopic (CEMS) measurements to learn more about the mechanism of corrosion of low carbon steel samples in aqueous sulfate and sulfite containing sulfate solutions (pH 3.5, 6.5 and 8.5). Passivation of iron in pure sulfate solution was studied in detail in earlier papers. In the present work, we used a solution containing both sulfate and sulfite anions to obtain more information about the effect of acid rain on low carbon steel samples. The compositions and thicknesses of the passive films formed due to the electrochemical treatments were determined from the CEM spectra. γ-FeOOH was found in each case on the surface of the samples; nevertheless, at pH 3.5 the sextet belonging to Fe3C appears in the CEM spectra, and also FeSO4 · H2O was detected in low concentration after the shortest polarization time (90 min). The results of the applied methods proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements referred to suppressed pitting at pH 8.5.

https://doi.org/10.1007/bf02072952