Masahiko Morinaga

Corrosion Behaviour of Nb-Based and Mo-Based Alloys in Liquid Na

The structural materials employed in advanced nuclear power systems (for example, a portable FBR) are exposed under severe environmental conditions [1–3]. Therefore, it is required for the materials to have super-heat resistance at 1473 K, high corrosion resistance to liquid metals and a life time of more than a decade of years. Both Nb-based and Mo-based alloys are ones of the candidate materials for such applications [4]. Since material lives are dominated by corrosion on several occasions, the compatibility of the material with liquid metals is indeed an important factor for the design and development of new materials. The corrosion behavior of stainless steels, which are widely used for the structural applications in nuclear power systems, have been investigated extensively [5–9]. However, the corrosion study is rather limited for Nb-based and Mo-based alloys. The purpose of this study is to obtain basic information on the corrosion in liquid Na for both the Nb-based and the Mobased alloys. In particular, our attention was directed towards the alloying effects on the corrosion of these alloys.