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

Abstract

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).