Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-628463
Understanding the effect of oxide ions on Solar Salt chemistry and corrosion mechanism of 316L stainless steel at 600 °C
- Solar Salt (60 wt% NaNO3, 40 wt% KNO3), used in Concentrated Solar Power (CSP) Thermal Energy Storage (TES) technology, can decompose into various products at elevated temperatures, with oxide ions being one of the known corrosive byproducts. The study mimics Solar Salt aging by intentionally adding sodium peroxide (Na2O2) and sodium oxide (Na2O) at concentrations of 0.005–0.33 wt% to investigate their role in the corrosion of austenitic stainless steel at 600 °C in typical operating conditions. Salt chemistry (nitrite, nitrate, oxide ions, and metal cations) was analyzed every 24 h, and steel corrosion after 168 h was assessed by weight change, corrosion rate, phase analysis, and cross-sectional morphology. Results reveal that at or above 0.135 wt% added Na2O2/Na2O leads to a quasi-steady-state equilibrium of oxide ions in the salt. Interestingly, at these concentrations, the presence of steel further decreases oxide ion concentration. Furthermore, above 0.135 wt%, the corrosion rateSolar Salt (60 wt% NaNO3, 40 wt% KNO3), used in Concentrated Solar Power (CSP) Thermal Energy Storage (TES) technology, can decompose into various products at elevated temperatures, with oxide ions being one of the known corrosive byproducts. The study mimics Solar Salt aging by intentionally adding sodium peroxide (Na2O2) and sodium oxide (Na2O) at concentrations of 0.005–0.33 wt% to investigate their role in the corrosion of austenitic stainless steel at 600 °C in typical operating conditions. Salt chemistry (nitrite, nitrate, oxide ions, and metal cations) was analyzed every 24 h, and steel corrosion after 168 h was assessed by weight change, corrosion rate, phase analysis, and cross-sectional morphology. Results reveal that at or above 0.135 wt% added Na2O2/Na2O leads to a quasi-steady-state equilibrium of oxide ions in the salt. Interestingly, at these concentrations, the presence of steel further decreases oxide ion concentration. Furthermore, above 0.135 wt%, the corrosion rate increases significantly, along with increased spallation, porosity and disintegration of the corrosion layer, forming a non-protective layer. This study highlights the critical role of oxide ions in the corrosion process.…


| Autor*innen: | Sumit Kumar, Srinivasan SwaminathanORCiD, Rene Hesse, Hennig Goldbeck, Wenjin Ding, Alexander Bonk, Thomas Bauer |
|---|---|
| Dokumenttyp: | Zeitschriftenartikel |
| Veröffentlichungsform: | Verlagsliteratur |
| Sprache: | Englisch |
| Titel des übergeordneten Werkes (Englisch): | Corrosion Science |
| Jahr der Erstveröffentlichung: | 2025 |
| Organisationseinheit der BAM: | 5 Werkstofftechnik |
| 5 Werkstofftechnik / 5.1 Mikrostruktur Design und Degradation | |
| Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
| Verlag: | Elsevier Ltd. |
| Jahrgang/Band: | 249 |
| Aufsatznummer: | 112849 |
| Erste Seite: | 1 |
| Letzte Seite: | 17 |
| DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
| Freie Schlagwörter: | Alkali oxides; Austenitic stainless steel; High temperature corrosion; Solar Salt; Thermal Energy Storage |
| Themenfelder/Aktivitätsfelder der BAM: | Material |
| Material / Degradationsmechanismen | |
| DOI: | 10.1016/j.corsci.2025.112849 |
| URN: | urn:nbn:de:kobv:b43-628463 |
| ISSN: | 1879-0496 |
| Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
| Lizenz (Deutsch): | Creative Commons - CC BY - Namensnennung 4.0 International |
| Datum der Freischaltung: | 03.04.2025 |
| Referierte Publikation: | Ja |
| Datum der Eintragung als referierte Publikation: | 03.04.2025 |
| Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |


