Abstract
Nodular corrosion takes place in cladding tubes of the boiling water reactor. In order to understand the mechanism of the nodular corrosion, a series of corrosion tests was performed with pure Zr and Zr-M binary alloys (M=Sn, Fe, Cr, Ni) by exposing them to the steam environment of 773 K and 10.3 MPa. The chemical composition of the oxide layer formed on the specimen surface was analyzed using X-ray photoelectron spectroscopy. As a result, it was found that the distribution of alloying elements, M, in the oxide layer was relatively uniform in the case of uniform corrosion, whereas it was very non-uniform in the case of nodular corrosion. For example, in the latter case, alloying elements such as Cr and Sn were condensed mainly in the outer surface of the oxide layer. Such a non-uniform distribution of alloying elements will not be arisen from the heterogeneous distribution of alloying elements in the mother alloy, but will be introduced to the oxide layer on the alloy in the course of corrosion. The segregation of alloying elements will disturb the uniform growth of the oxide layer, resulting in the onset of nodular corrosion on the surface.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Japan Institute of Metals and Materials
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
