Impurity driven corrosion behavior of HAYNES® 230® alloy in molten chloride Salt

Abstract

The impurity-driven corrosion behavior of HAYNES® 230® alloy in the molten KCl-MgCl2-NaCl salt was studied at 800 °C for 100 h with different salt purity conditions. It was found that HAYNES® 230® alloy exhibited better corrosion resistance in the salt with lower impurities. Furthermore, the corrosion (non-immersion) due to molten salt vapors was more severe at higher temperature. The attack was localized and driven by outward diffusion of chromium through the grain boundaries. The presence of Mg in its metal form in the salt resulted in an even higher mass-loss in HAYNES® 230® alloy due to Mg-Ni interaction.