Performance of Sc-Y-ODS variant of Eurofer steel in stagnant PbLi at 600°C

Abstract

This paper represents a part of the research of structural materials for fusion systems. The performance of a conventionally formed Eurofer-97 steel and its Sc-Y-ODS variant developed by our group was assessed in a stagnant liquid PbLi environment. The experiments were performed at 600°C for 500 and 1000 hours, and the subsequent microscopical investigation identified a solution-based attack as the dominant corrosion damage of both materials. The metal loss of the conventional Eurofer-97 steel was 66.2 µm after 1000 h exposure, corresponding to a rate of 580 µm/year. In contrast, the ODS Eurofer variant strengthened with various fine Sc-Y complex oxides showed a 70% lower corrosion damage, mainly owing to formation of a Sc-Y-rich Pb surface layer. To understand the degradation process in more detail, both materials were characterized before and after the PbLi exposure in terms of their microstructures and mechanical behavior including hardness, tensile, impact and static fracture toughness tests.