Direct and indirect contact of an austenitic high-temperature alloy to eutectic chloride melts with possible consequences for inhibitor strategies

There is an inevitable difference between direct and indirect contact of metals with eutectic chloride melts defined by the gas phase impurity content, here, humidity oxygen in argon. The impurities-to-salt ratio will always be higher allowing for a more aggressive attack on metal components. This effect has been studied decommissioned container from experimental high-temperature setup, which never melt but its evaporated species; vessel lasted only short time, 700 h. It was found that suffered severe damage when exposed to salt species than melt; estimated thickness loss per year almost three-fold contact. In contrast 253MA fully immersed MgCl2-KCl, magnesium not most-active cationic causing corrosion wall instead, it potassium. Consequently, this unexpected observation needs carefully considered design Gen3-CSP storage tank applied inhibitor strategy.