Corrosion Behavior of L-Pbf 316l Stainless Steel Exposed to Different Molten Salts Used as Thermal Energy Storage Materials

Abstract

The high-temperature corrosion behavior of the L-PBF 316L stainless steel has been evaluated in presence of different molten solar salts. The samples were characterized by XRD and SEM/EDX after immersion tests. Their aggressiveness followed the sequence: Hitec < LiNaKCO3 < NaKMgCl < NaKZnCl. There was not a great reaction of the L-PBF 316L with the Hitec salt. However, the high activity of Li+ in the LiNaKCO3 molten salts produced the formation of LiFeO2 and LiCrO2. In the samples exposed to chloride-based molten salts, the attacked zone was much deeper and the corrosion process obeys an electrochemical corrosion mechanism.

Keywords: 316L Stainless Steel, L-PBF, Molten Salt Corrosion, Thermal energy storage, Concentrated Solar Plant