| About this Abstract |
| Meeting |
2024 TMS Annual Meeting & Exhibition
|
| Symposium
|
Materials Corrosion Behavior in Advanced Nuclear Reactor Environments
|
| Presentation Title |
New Insights into the Internal Oxidation Mechanism of 15-15Ti in the Lead-bismuth Eutectic Coolant |
| Author(s) |
Min Wang, Cheng-xu Lu, Ying-che Ma |
| On-Site Speaker (Planned) |
Min Wang |
| Abstract Scope |
Though providing corrosion protection, internal oxidation generally induces a metal recession. The lead-bismuth eutectic corrosion mechanism, especially the advancing behavior of the oxide/metal (O/M) interface, was investigated at 550 and 600℃ for a candidate LFR cladding material, the austenitic stainless steel 15-15Ti. Island-like Ni-rich areas are often found in the spinel layer and are commonly considered oxidation residues by researchers. However, through special sample preparation, we discovered that these Ni-rich areas in fact originate from the unoxidized metal near the O/M interface. FIB-STEM characterizations show that Ni-rich areas act as Cr-suppliers and Ni-receivers during oxidation, facilitating the O-consumption by Cr-oxidation. Moreover, Ni-rich areas preferentially nucleate on the grain boundary coherently and then grow forward inducing grain boundary migration, obstructing oxygen diffusion by serrating its pathway. The effects of Si addition and Al addition on the anti-corrosion performance promotion, oxide structure, and corrosion mechanisms of 15-15Ti are also studied. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Characterization, Phase Transformations |