Characterization of ODS (Oxide Dispersion Strengthened) Eurofer/Eurofer dissimilar electron beam welds

Abstract Breeding blanket fabrication will need the assembly of reduced activation ferritic martensitic steels and their ODS alloyed grades. Dissimilar electron beam welds were performed using 6 mm thick Y2O3 ODS Eurofer and Eurofer 97/2 samples. Thereafter, an austenitization step and an annealing post-weld heat treatment were applied. The joining process was qualified using the microstructural and mechanical properties characterization of as-welded and post-weld heat treated samples. The results show that electron beam welding is efficient for joining dissimilar ODS Eurofer/Eurofer materials and that a further PWHT (post-weld heat treatment) is required. The weld microstructure presents large oxide particles that are detrimental to mechanical properties. However, the mechanical properties are improved compared to similar Eurofer joints and they are approaching Eurofer behavior.