In this work, complex corrosion products on a superheater tube exposed to biomass firing were characterized by the complementary use of energy-dispersive synchrotron diffraction, electron microscopy, and energy-dispersive X-ray spectroscopy. Non-destructive synchrotron diffraction in transmission geometry measuring with a small gauge volume from the sample surface through the corrosion product allowed depth-resolved phase identification and revealed the presence of (Fe,Cr)2O3 and FeCr2O4. This was supplemented by microstructural and elemental analysis correlating the additional presence of a Ni-rich austenite phase to selective removal of Fe and Cr from the alloy, via a KCl-induced corrosion mechanism. Compositional variations were related to diffraction results and revealed a qualitative influence of the spinel cation concentration on the observed diffraction lines.
- Stainless steel
- (Synchrotron) X-ray diffraction
- High-temperature corrosion
Okoro, S. C., Nießen, F., Villa, M., Apel, D., Montgomery, M., Jappe Frandsen, F., & Pantleon, K. (2017). Complementary Methods for the Characterization of Corrosion Products on a Plant-Exposed Superheater Tube. Metallography, Microstructure, and Analysis, 6(1), 22–35. https://doi.org/10.1007/s13632-016-0325-6