Subjects: Nuclear Science and Technology >> Engineering Technology of Fission Reactor submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: To investigate the corrosion products of Cr in molten FLiNaK salt (46.5 mol% LiF–11.5 mol% NaF–42 mol% KF), the corrosion test of the pure metal Cr was performed in molten FLiNaK salt at 700 ℃ for 200 h. The FLiNaK salt after the corrosion test was thoroughly investigated by X-ray absorption near-edge structure spectroscopy, a transmission electron microscope, and X-ray diffraction. The results demonstrate that the predominant oxidation state of Cr in FLiNaK salt is Cr3+, and the main corrosion product in cooled FLiNaK salt is K2NaCrF6.
Subjects: Nuclear Science and Technology >> Particle Accelerator submitted time 2023-06-18 Cooperative journals: 《Nuclear Science and Techniques》
Abstract: Microstructure and oxidation behavior of modified Ni-16Mo-7Cr-4Fe alloys by yttrium microalloying were investigated by scanning electron microscopy, transmission electron microscopy, grazing incident X-ray diffraction and synchrotron radiation X-ray fluorescence. M6C and Ni17Y2 phases were observed and the amount of Ni17Y2 increased with yttrium concentration. When the yttrium concentration increased to 0.43wt.%, some Ni17Y2 chains and multi phase regions containing Ni17Y2, M6C and γ phase appeared, which is harmful for the oxidation resistance. The alloy containing 0.05wt.% yttrium showed the best oxidation resistance, which derives its oxidation resistance from the adequate concentration of yttrium in the solid-solution (γ phase), the formation of the protective layer of YCrO3 and chromia oxide and the strengthening effect of yttrium on oxide boundaries.