journal article·2023-11Open access

Differential aeration corrosion of silver in sulfate melts at 900 °C

D. Diomande, S. Mathieu, P.J. Panteix, M. Siblani, L. Aranda, C. Petitjean, M. Vilasi

Corrosion Science· Volume 224

Abstract

The thermodynamic of the Ag / Ag 2 SO 4 electrode, serving as reference for carrying electrochemical experiences of corrosion in sulfates at 900 °C, was investigated because of the observed limited operating lifetime. Its use led to the total degradation of the ∅1 mm Ag wire in ∼200 h. Half-immersion of Ag wires in sulfates mixes (selected for their acido-basicity) evidenced the homogeneous thinning of the immersed part of the wires and the precipitation of metallic Ag in the salt. The different steps governing the corrosion mechanism were proposed considering that the driving force was the differential aeration of the Ag wire.
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Research context

OpenAlex topics: Metallurgical Processes and Thermodynamics · Molten salt chemistry and electrochemical processes · Corrosion Behavior and Inhibition

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (30)

Show source-provided references
1. Electrochemical aspects of molten-salt-enhanced corrosion10.1016/0025-5416(87)90397-1 ↗
2. Chemistry and electrochemistry of hot corrosion of metals10.1016/0025-5416(87)90394-6 ↗
3. Corrosion of metals and alloys in molten glasses. Part 2: nickel and cobalt high chromium superalloys behaviour and protection10.1016/j.corsci.2003.10.025 ↗
4. Corrosion of metals and alloys in molten glasses. Part 1: glass electrochemical properties and pure metal (Fe, Co, Ni, Cr) behaviours10.1016/j.corsci.2003.10.024 ↗
5. Electrochemical behavior of gold, palladium and platinum as inert anode materials for molten chloride electrolysis10.1016/j.electacta.2022.141598 ↗
6. Electrochemical behavior of iodide ions in molten fluoride salts10.1016/j.electacta.2023.142019 ↗
7. Redox properties of the carbonate molten salt Li2CO3Na2CO3-K2CO310.1016/j.electacta.2021.139765 ↗
8. Electrochemical reactions in a pure Na2SO4 melt10.1149/1.2119581 ↗
9. D.A. Shores, R.C. John, A study of the Ag(s)/Ag2SO4 +Na2SO4(l) reference electrode, (n.d.) 9.
10. Corrosion of nickel in sodium sulphate-sodium chloride melts. part I10.1007/BF00617672 ↗
11. Electrochemical characterization of chromia- and alumina-forming nickel-based superalloys in molten silicates
12. The hot corrosion of metals by Molten salts10.1149/198110.0159PV ↗
13. C.O. Park R. Rapp Electrochem. React. Molten Na2SO4 900 133 1986.10.1149/1.2108981 ↗
14. Duret-Thual · 1986
15. Hot corrosion of preoxidized Ni by a thin fused Na2SO4 film at 900°C10.1149/1.2086436 ↗
16. A comparison of reference electrodes in molten sodium sulfate
17. Die stabilität von Ag/Ag2SO4 referenzelektroden für untersuchungen in geschmolzenen salzen10.1016/0013-4686(70)85019-8 ↗
18. Knacke · 1991
19. Barin · 1989
20. Barin · 1993
21. Thermodynamic description of the ternary systems of the core sulphate system Na2SO4–K2SO4–MgSO4–CaSO410.1016/j.calphad.2021.102313 ↗
22. Über die Verbindungen von magnesium- und natriumsulfat10.1002/zaac.19090610112 ↗
23. Landolt · 1993
24. Transport of oxidant in molten Na2SO4 in O2‐SO2 ‐SO3 environments10.1149/1.2127417 ↗
25. Thermochemical Data of Pure Substances, Wiley Online Libr. (n.d.). https://doi.org/10.1002/9783527619825.10.1002/9783527619825 ↗
26. OpenLibrary.org, Thermochemical properties of inorganic substances (1991 edition), Open Libr. (n.d.). https://openlibrary.org/books/OL1545875M/Thermochemical_properties_of_inorganic_s bstances (accessed April 7, 2023).
27. Equations for transport in solid oxides and sulfides of transition metals10.1016/0079-6786(75)90002-3 ↗
28. M. Temkin Mixtures fused salts Ion. Solut. 1945 411 420.
29. Electrochemical studies of molten alkali sulphates10.1016/0013-4686(70)87004-9 ↗
30. R. Malacarne, S. Mathieu, L. Aranda, D. Diomande, C. Desgranges, S. Knittel, M. Vilasi, On the corrosion behavior of A718 and AD730TM polycrystalline nickel-based alloys and the role of SO3 in the hot corrosion mechanism, (n.d.).