Fusion Science and Technology / Volume 56 / Number 1 / July 2009 / Pages 190-194
Tritium, Safety, and Environment / Eighteenth Topical Meeting on the Technology of Fusion Energy (Part 1)
Molten salt LiF-BeF2 (Flibe) is one of candidates for self-cooled tritium breeder in fusion blanket system. The Ni based alloys of Hastelloy C-276 (6.28Fe, 15.67Cr, 0.42Mn, 15.83Mo, 3.34W, Ni as balance), Inconel 600(7.02Fe, 15.75Cr, Ni as balance) and Inconel 625 (4.12Fe, 21.94Cr, 9.10Mo, Ni as balance) are candidates of structural material of blanket loop components at down stream. Corrosion characteristics of these alloys were investigated by corrosion test in static Flibe at 500°C and 600°C for 1000 hours. The corrosion rates were estimated from the weight losses of specimens, and those of Hastelloy C-276, Inconel 600 and Inconel 625 in Flibe at 600°C were 3.4m/year, 2.8m/year and 1.1m/year, respectively. The mass balance between the weight losses of specimens and the increase of impurity in Flibe by the exposure was investigated, and it was found that the corrosion was mainly caused by the depletion of Cr from the alloys. The corroded surface had high Ni concentration after the Cr depletion by corrosion, and this is expected to be corrosion resistant in Flibe.