Corrosion behavior of Fe–Ni–Cr alloys in the molten salt of LiCl–Li 2O at high temperature

Abstract

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%Li 2O mixture at temperatures ranging from 923 to 1123 K. In molten LiCl, dense protective scale of LiCrO 2 grows outwardly while corrosion is accelerated by addition of Li 2O to LiCl. The basic fluxing of Cr 2O 3 by Li 2O would be the cause of accelerated corrosion. Because of low oxygen solubility and very high Li 2O activity in the molten LiCl–Li 2O mixture, Cr is preferentially corroded while Ni remains stable and thus, corrosion rate of the alloys in molten LiCl–Li 2O mixture increases with an increase in Cr content.