Abstract
Stainless steel is a ubiquitous structural material and one that finds extensive use in core-internal components in nuclear power plants. Stainless steel features superior corrosion resistance (e.g., as compared to ordinary steel) due to the formation of passivating iron and/or chromium oxides on its surfaces. However, the breakdown of such passivating oxide films, e.g., due to localized deformation and slip line formation following exposure to radiation, or aggressive ions renders stainless steel susceptible to corrosion-related degradation. Herein, the effects of alkali cations (i.e., K+, Li+) and the interactions between the passivated steel surface and the solution are examined using 304L stainless steel. Scanning electrochemical microscopy and atomic force microscopy are used to examine the inert-to-reactive transition of the steel surface both in the native state and in the presence of applied potentials. Careful analysis of interaction forces, in solution, within ≤10 nm of the steel surface, reveals that the interaction between the hydrated alkali cations and the substrate affects the structure of the electrical double layer (EDL). As a result, a higher surface reactivity is indicated in the presence of Li+ relative to K+ due to the effects of the former species in disrupting the EDL. These findings provide new insights into the role of the water chemistry not only on affecting metallic corrosion but also in other applications, such as batteries and electrochemical devices.
| Original language | English |
|---|---|
| Pages (from-to) | 14680-14688 |
| Number of pages | 9 |
| Journal | ACS Omega |
| Volume | 3 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 1 2018 |
Funding
The authors acknowledge financial support for this research provided by the U.S. Department of Energy\u2019s Light Water Reactor Sustainability (LWRS) Program through the Oak Ridge National Laboratory operated by UT-Battelle LLC (Contract #: 4000154999) and The National Science Foundation (CAREER Award: 1253269). The contents of this paper reflect the views and opinions of the authors, who are responsible for the accuracy of data presented. This research was carried out in the Laboratory for the Chemistry of Construction Materials (LC2) and the California Nanosystems Institute at UCLA. As such, the authors gratefully acknowledge the support that has made these facilities and their operations possible.