Corrosion behavior of Fe–Ni–Cr alloys in the molten salt of LiCl–Li2O at high temperature

At Korea Atomic Energy Research Institute (KAERI), we investigated the corrosion behavior of a series of Fe–Cr–Ni alloys with different chromium contents in molten LiCl and molten LiCl–25wt%Li2O mixture at temperatures ranging from 923 to 1123 K. In molten LiCl, dense protective scale of LiCrO2 grows outwardly while corrosion is accelerated by addition of Li2O to LiCl. The basic fluxing of Cr2O3 by Li2O would be the cause of accelerated corrosion. Because of low oxygen solubility and very high Li2O activity in the molten LiCl–Li2O mixture, Cr is preferentially corroded while Ni remains stable and thus, corrosion rate of the alloys in molten LiCl–Li2O mixture increases with an increase in Cr content.