High-resolution transmission electron microscopy and atom probe tomography are used to characterize the initial passivation and subsequent intergranular corrosion of degraded grain boundaries in a model Ni-30Cr alloy exposed to 360 °C hydrogenated water. Upon initial exposure for 1000 h, the alloy surface directly above the grain boundary forms a thin passivating film of Cr 2 O 3 , protecting the underlying grain boundary from intergranular corrosion. However, the metal grain boundary experiences severe Cr depletion and grain boundary migration during this initial exposure. To understand how Cr depletion affects further corrosion, the local protective film was sputtered away using a glancing angle focused ion beam. Upon further exposure, the surface fails to repassivate, and intergranular corrosion is observed through the Cr-depleted region. Through this combination of high-resolution microscopy and localized passive film removal, we show that, although high-Cr alloys are resistant to intergranular attack and stress corrosion cracking, degradation-induced changes in the underlying metal at grain boundaries make the material more susceptible once the initial passive film is breached.
Kruska, K., et al. "Intergranular corrosion of Ni-30Cr in high-temperature hydrogenated water after removing surface passivating film." npj Materials Degradation, vol. 8, no. 1, Mar. 2024. https://doi.org/10.1038/s41529-024-00442-0
Kruska, K., Olszta, M. J., Wang, J., & Schreiber, D. K. (2024). Intergranular corrosion of Ni-30Cr in high-temperature hydrogenated water after removing surface passivating film. npj Materials Degradation, 8(1). https://doi.org/10.1038/s41529-024-00442-0
Kruska, K., Olszta, M. J., Wang, J., et al., "Intergranular corrosion of Ni-30Cr in high-temperature hydrogenated water after removing surface passivating film," npj Materials Degradation 8, no. 1 (2024), https://doi.org/10.1038/s41529-024-00442-0
@article{osti_2323593,
author = {Kruska, K. and Olszta, M. J. and Wang, J. and Schreiber, D. K.},
title = {Intergranular corrosion of Ni-30Cr in high-temperature hydrogenated water after removing surface passivating film},
annote = {Abstract High-resolution transmission electron microscopy and atom probe tomography are used to characterize the initial passivation and subsequent intergranular corrosion of degraded grain boundaries in a model Ni-30Cr alloy exposed to 360 °C hydrogenated water. Upon initial exposure for 1000 h, the alloy surface directly above the grain boundary forms a thin passivating film of Cr 2 O 3 , protecting the underlying grain boundary from intergranular corrosion. However, the metal grain boundary experiences severe Cr depletion and grain boundary migration during this initial exposure. To understand how Cr depletion affects further corrosion, the local protective film was sputtered away using a glancing angle focused ion beam. Upon further exposure, the surface fails to repassivate, and intergranular corrosion is observed through the Cr-depleted region. Through this combination of high-resolution microscopy and localized passive film removal, we show that, although high-Cr alloys are resistant to intergranular attack and stress corrosion cracking, degradation-induced changes in the underlying metal at grain boundaries make the material more susceptible once the initial passive film is breached. },
doi = {10.1038/s41529-024-00442-0},
url = {https://www.osti.gov/biblio/2323593},
journal = {npj Materials Degradation},
issn = {ISSN 2397-2106},
number = {1},
volume = {8},
place = {United Kingdom},
publisher = {Nature Publishing Group},
year = {2024},
month = {03}}
Olszta, Matthew J.; Schreiber, Daniel K.; Thomas, Larry E.
Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactorshttps://doi.org/10.1007/978-3-319-48760-1_19
Toloczko, Mychailo B.; Olszta, Matthew J.; Bruemmer, Stephen M.
Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems — Water Reactorshttps://doi.org/10.1007/978-3-319-48760-1_7