Studies on chemical compatibility of steels with liquid lithium

Interaction of steel specimens such as SS 316 LN, D9, 9Cr–1Mo, oxide dispersed steel (ODS) and pure iron with liquid lithium has been studied at 823 and 973 K (550 and 700 °C) for various durations from 250 to 1000 h at 250 h intervals. The relevance of this study is to identify a suitable container material for liquid lithium which has been proposed as a liquid poison to control the reactivity in nuclear reactors. The metallic specimens were characterised before and after exposure to liquid lithium by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) and mechanical testing. The results indicate that except for pure iron, lithium interacts with all steel samples in varying degree. The depth of interaction varies from 20 to 60 μm depending on nature of specimen, temperature and time of exposure.