LiCl-Li2O Molten Research Articles

Corrosion behavior of Fe–Ni–Cr alloys in the molten salt of LiCl–Li 2O 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%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.

Corrosion study of NiAl–28Cr–5.8Mo–0.2Hf alloy in molten LiCl–10 wt.%Li 2O

Corrosion of the reduction vessel induced by molten LiCl–Li 2O is an important problem in the lithium reduction technique for the spent nuclear fuel management. This study investigates the corrosion of NiAl–28Cr–5.8Mo–0.2Hf alloy in the molten LiCl–10 wt.%Li 2O at 750 °C by immersion experiments. The alloy is mainly composed of NiAl(β) phase and Cr(Mo) phase. The corrosion scale is composed of LiCrO 2 and LiAlO 2.The NiAl(β) phase is corroded slowly because of the depletion of Al near the phase boundaries, but the Cr(Mo) phase undergoes fast corrosion, which results in that the corrosion of Cr(Mo) phase is preceded over that of the NiAl(β) phase in the molten LiCl–10 wt.%Li 2O. The corrosion kinetic curve shows a linear pattern, which is mainly attributed to the fast corrosion of Cr(Mo).