The corrosion behavior of 304 stainless steel was studied at 450 °C in both molten and vapor forms of NaNO-NaCl-NaF salt, revealing noticeable weight loss and the formation of surface oxides like FeO and FeCrO.
A corrosion layer of about 1.1 μm was noted to be more homogeneous in molten salt, while in vapor, the oxide distribution was uneven with shedding issues attributed to gas presence affecting adhesion.
The corrosion rate in molten salt was found to be nearly the same as that in solar salt, suggesting that the combined effects of Cl and F ions on corrosion are minimal, contributing valuable data for materials selection in Concentrated Solar Power (CSP) applications.