Temperature-Dependent Molten Chloride Salt Corrosion of Nickel Alloys

Abstract

As next-generation clean and renewable energy technologies like concentrating solar power (CSP) systems and molten salt-cooled reactors (MSR) operate at ever higher temperatures (HT) to increase efficiency, their structural material and molten salt selection becomes increasingly important. To understand the corrosion behavior of candidate alloys to be used as materials for storage tanks, heat exchangers, and piping, seven alloys (Hastelloy N, Haynes 242, Haynes 214, Hastelloy C-276, Haynes 230, Haynes 224, Haynes 244) are immersed in purified 45.8 MgCl2- 38.5 KCl- 15.7 NaCl wt% chloride salt for 100 hours at 650°, 725°, and 800°C. After the exposure tests, the alloys are analyzed using SEM and EDS to determine the extent of salt infiltration and primary corrosion mechanisms. In addition, room-temperature XRD analysis provides quantitative information about the alloys’ corrosion products. These findings contribute important insight for molten salt energy system communities.