Tuzi, S.; Stiller, K.; Thuvander, M. Oxidation of Alloy X-750 with Low Iron Content in Simulated BWR Environment. J. Nucl. Eng.2023, 4, 711-722.
Tuzi, S.; Stiller, K.; Thuvander, M. Oxidation of Alloy X-750 with Low Iron Content in Simulated BWR Environment. J. Nucl. Eng. 2023, 4, 711-722.
Tuzi, S.; Stiller, K.; Thuvander, M. Oxidation of Alloy X-750 with Low Iron Content in Simulated BWR Environment. J. Nucl. Eng.2023, 4, 711-722.
Tuzi, S.; Stiller, K.; Thuvander, M. Oxidation of Alloy X-750 with Low Iron Content in Simulated BWR Environment. J. Nucl. Eng. 2023, 4, 711-722.
Abstract
This paper presents an investigation of the oxidation of Alloy X-750 containing 5% Fe in a simulated boiling water reactor (BWR) environment. To mimic the conditions in which the bare metal is exposed to the reactor water the samples were not pre-oxidized. The specimens were exposed for durations ranging from 2 to 840 hours, and the development of the oxide microstructure was mainly studied using electron microscopy. The results showed that the oxide scale consisted of blocky crystals of trevorite on top of a porous inner layer rich in Ni and Cr. After the longest exposure time, the trevorite crystals completely covered the specimen surface. The study further revealed that the speed at which the oxide grew and the metal dissolved both decreased with time. Additionally, the metal thinning process was found to be sub-parabolic. Given the significant variation in iron content in the X-750 specification, the influence of this element on the material's corrosion performance in BWR was examined by comparing the results from this investigation with those from previous work on material containing 8 wt% Fe. The study demonstrated that the oxide growth, metal dissolution and metal thinning were slower in the material with higher Fe content, indicating the importance of this element in limiting the degradation of Alloy X-750 in BWR environments.
Keywords
oxidation; boiling water reactor; spacer; autoclave corrosion testing
Subject
Chemistry and Materials Science, Metals, Alloys and Metallurgy
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
