Mechanical properties and microstructure characterization of unirradiated Eurofer-97 steel variants for the EUROfusion project

STEM imaging of irradiation induced defects in Eurofer97 steel variants irradiated in the EUROfusion collaboration

“…As revealed in Ref. [1], in nonirradiated state TEM/STEM characterization of H series steel had revealed that two types of precipitate families: (i) predominantly Ta, V and N rich precipitates which are expected to be the MX precipitates and (ii) predominantly Cr, W rich phases, which are expected to be M23C6 carbides. Because all the strong carbide formers typically enter M23C6 phase, these particles also showed presence of Ta and V. For convenience, the STEM-EDX mapping result from the unirradiated H series steel are shown in Figure 5 where the two types of precipitate families can be identified.…”

“…For the sake of completeness, the nonirradiated results of the ten steels are also presented here, that are adapted from Ref. [1]. Here, one must note that characterizing the dislocation loop microstructure of RAFM steels is critical to understand the hardening/embrittlement behavior.…”

“…Figure 24 and Figure 25 show BF and MAADF images of the sample showing the typical lath structure in material L, adapted from Ref. [1]. Large carbides were detected along the lath boundaries, which are expected to be the M23C6 or M7C3 type [3].…”

“…For convenience, the nonirradiated microstructure and the STEM-EDX mapping results that were reported in Ref. [1] are shown in Figure 1. After irradiation, no significant evolution of the precipitation distribution occurred.…”

“…The mechanical properties and multi-length scale characterization of the microstructures of these ten steels, designated as H, I, P, J, K, L, M, N, O, P and reference E, in the nonirradiated form was reported in Ref. [1] while their irradiated properties and some microstructure analysis was reported in Ref. [2].…”