About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
Presentation Title |
A Mechanistic Study on Dealloyed-induced Stress Corrosion Cracking Initiation of Alloy 800 |
Author(s) |
Hooman Gholamzadeh, Adil Shaik, Kevin Daub, Matt Topping, Mark Daymond, Suraj Y. Persaud |
On-Site Speaker (Planned) |
Suraj Y. Persaud |
Abstract Scope |
Despite their good resistance to general and localized corrosion, Fe- and Ni-based alloys can suffer from environmentally assisted cracking. Alloy 800 (Fe-32Ni-21Cr), for instance, has shown excellent in-service performance as the tubing material of CANDU steam generators for decades. However, this material can suffer from selective dissolution (dealloying) and stress corrosion cracking (SCC) in boiling caustic environments, where Fe and Cr are soluble. Dealloying results in formation of a brittle, nanoporous film enriched in the more noble element. This film may be a precursor to SCC via a cleavage mechanism. The mechanism of dealloying-induced SCC initiation in Alloy 800 is investigated at the nanoscale in boiling caustic solutions. Several state-of-the-art electron microscopy techniques are used to characterize the nanoscale chemistry and plastic deformation associated with crack initiation from a dealloyed layer. Results suggest that, upon fracture, a dealloyed layer may inject a high-energy micro-crack into the substrate material, initiating SCC. |
Proceedings Inclusion? |
Planned: |
Keywords |
Environmental Effects, Mechanical Properties, Nuclear Materials |