6533b7d7fe1ef96bd1268cbf

RESEARCH PRODUCT

A corrosion study of austenitic and martensitic steels under boiler conditions by means of 57Fe conversion electron mössbauer spectroscopy

R. GrimmJ. GrüberPhilipp GütlichJ. FleischJürgen Ensling

subject

AusteniteMaterials scienceScanning electron microscopeGeneral Chemical EngineeringMetallurgyOxideGeneral ChemistryCorrosionchemistry.chemical_compoundchemistryConversion electron mössbauer spectroscopyMartensiteGeneral Materials ScienceIncoloyMagnetite

description

Abstract The growth of protective oxide layers on a martensitic FeCr (1.4122) and two austenitic FeCrNi steel samples (1.4550 and Incoloy 800) was studied by means of the 57Fe Conversion Electron Mossbauer Spectroscopy (CEMS). Scanning electron microscopy was applied to characterize the topographical nature of the oxide layers. Following a technical procedure of running-in steam generators, the steel specimens were oxidized in oxygen-free water at 295°C, 142 bar and a pH value between 9 and 10 for periods up to 70 h. In the case of the steels 1.4122 and 1.4550 the only oxide phase detected was non-stoichiometric magnetite, whereas nickel ferrite of nonstoichiometric composition was found on Incoloy 800. The study of the kinetics of the oxide layer growth revealed that the oxidation process is most probably controlled by short-circuit diffusion.

yearjournalcountryeditionlanguage
1978-01-01Corrosion Science
https://doi.org/10.1016/0010-938x(78)90016-1