Hot corrosion behavior of ni-base superalloys in a lithium molten salt

• Published in: Metals and materials international 2009, 15(1), , pp.51-55
• Main Authors: Cho, Soo-Haeng, Hong, Sun-Suk, Kang, Dae-Seung, Hur, Jin-Mok, Lee, Han-Soo
• Format: Article
• Language: English
• Subjects: Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chromium oxides; Corrosion; Corrosion products; Corrosion resistance; Engineering Thermodynamics; Heat and Mass Transfer; Lithium; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Nickel base alloys; Processes; Reduction (electrolytic); Solid Mechanics; Superalloys; 재료공학
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-009-0051-6

The electrolytic reduction of a spent oxide fuel involves the liberation of the oxygen in a molten LiCl electrolyte, which is a chemically aggressive environment that is too corrosive for typical structural materials. Accordingly, it is essential to choose the optimum material for the process equipments such as the electroreducer and the salt purification vessel in the pyrochemical process. In this study, the corrosion behaviors of superalloys N-1, N-2 and N-3 in a molten LiCl-Li 2 O salt under an oxidizing atmosphere were investigated at 650 °C for 72 h to 216 h. Superalloy N-1 showed the highest corrosion resistance among the examined alloys. The corrosion products of superalloys N-1 and N-2 were NiO, Cr 2 O 3 , and NiCr 2 O 4 , while NiO, Cr 2 O 3 , LiAl 2 Cr 3 O 8 were identified as the corrosion products of superalloy N-3. For superalloy N-1, its outer corrosion layer was more continuous, dense and adherent compared to those of N-2 and N-3.