High-temperature corrosion of UNS N10003 in molten Li2BeF4 (FLiBe) salt
- Univ. of Wisconsin, Madison, WI (United States)
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
Here, corrosion testing of Hastelloy N in molten fluoride salt was performed in purified molten 27LiF-BeF2 (66-34mol%) (FLiBe) salt at 700°C for 1000 hours, in pure nickel and graphite capsules. In the nickel capsule tests, the near-surface region of the alloy exhibited an about 200 nm porous structure, an approximately 3.5 μm chromium depleted region, and MoSi2 precipitates. In tests performed in graphite capsules, the alloy samples gained weight due to the formation of a variety of Cr3C2, Cr7C3, Mo2C and Cr23C6, carbide phases on the surface and in the subsurface regions of the alloy. A Cr depleted region was observed in the near-surface region where Mo thermally diffused toward either surface or grain boundary, which induced approximately 1.4 μm Ni3Fe alloy layer in this region. The carbide containing layer extended to about 7 μm underneath the Ni3Fe layer. The presence of graphite dramatically changes the mechanisms of corrosion attack in Hastelloy N in molten FLiBe salt. Evaluated by in terms of the depth of attack, graphite clearly accelerates corrosion, but the results appear to indicate that the formation of Cr23C6 phase might stabilize the Cr and mitigate its dissolution in molten FLiBe salt.
- Research Organization:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC07-05ID14517
- OSTI ID:
- 1273151
- Journal Information:
- Corrosion, Vol. 71, Issue 10; ISSN 0010-9312
- Publisher:
- NACE InternationalCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Synchrotron radiation-based materials characterization techniques shed light on molten salt reactor alloys
|
journal | December 2019 |
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