(351f) Compatibility of Ni-Cr Alloys in Static and Flowing Commercial Molten Chloride Salt

The next generation of concentrating solar power (CSP) plants will require thermal storage to enable dispatchable renewable energy. One storage option to achieve >50% electrical efficiency at >700°C is chloride salts. To evaluate the compatibility of commercial Ni-Cr alloys in MgCl₂-KCl-NaCl salt from a commercial source, a laboratory purification process was used to minimize the O, S and Br in the starting salt. The first stage evaluated commercial Ni-based alloys such as 230 (Ni-22Cr-12W) and 600 (Ni-16Cr-9Fe) under isothermal conditions in a sealed Ni or Mo capsule at 600°-800°C. At 800°C, multiple experiments are being conducted with the same conditions to evaluate reproducibility of mass change as well as depth of Cr dissolution, which is the typical alloy degradation mechanism in halide salts. The second stage of the work will evaluate the compatibility of alloy 600 in flowing salt using a thermal convection loop where a temperature gradient is more representative of the CSP application. This research is sponsored by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Solar Energy Technology Office.