Ulbricht Andreas, Heinemann André, Bergner Frank
Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden, Germany.
German Engineering Materials Science Centre (GEMS), Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Geesthacht GmbH, D-85748 Garching, Germany.
J Appl Crystallogr. 2022 Jun 15;55(Pt 4):702-712. doi: 10.1107/S1600576722004800. eCollection 2022 Aug 1.
Ferritic/martensitic (F/M) Fe-Cr-based steels are candidates for applications in nuclear fission and fusion. Previous experimental results for neutron-irradiated binary Fe-Cr alloys and high-dose neutron-irradiated F/M steels contributed greatly to the understanding of the irradiation behaviour of these groups of materials. However, some details still need to be addressed. Such gaps are related to the effect of secondary alloying and impurity elements, such as Ni and Si, as well as the dose dependence at lower neutron doses [ in the range 0.1-1 displacements per atom (dpa)]. This input is essential, for example, for multiscale modelling of irradiation effects or the evaluation of nuclear fission or fusion components at the first stages of operation. Using small-angle neutron scattering, three issues are addressed: (1) the effect of Cr undersaturation (5% Cr) and supersaturation (14% Cr) on the formation of irradiation-induced solute atom clusters/precipitates in low-dose neutron-irradiated Fe-Cr alloys in the presence of intentionally added levels of Ni, Si and P; (2) the effect of irradiation temperature (290°C versus 450°C); and (3) the effect of neutron dose in the range 0.06-0.6 dpa on the irradiation response of the reduced-activation F/M 9%Cr steel Eurofer97. The irradiation-enhanced formation of Cr-rich α'-phase particles was found to be the dominant effect for supersaturated Fe-14Cr-NiSiP at both irradiation temperatures. In contrast, α' formation is impossible in Fe-5Cr-NiSiP, for which the pronounced irradiation effects observed at 0.1 dpa are mainly attributed to added Ni, Si and P. Finally, Eurofer97 exhibits an exceptionally weak irradiation effect at low neutron doses, the reasons for which are also considered.
铁素体/马氏体（F/M）铁铬基钢是核裂变和核聚变应用的候选材料。先前对中子辐照二元铁铬合金和高剂量中子辐照F/M钢的实验结果，对理解这些材料组的辐照行为有很大帮助。然而，一些细节仍需解决。这些差距与次要合金元素和杂质元素（如镍和硅）的影响有关，也与较低中子剂量（在每原子0.1 - 1位移(dpa)范围内）下的剂量依赖性有关。例如，这一信息对于辐照效应的多尺度建模或运行初期核裂变或聚变部件的评估至关重要。利用小角中子散射，解决了三个问题：(1) 在有意添加一定水平的镍、硅和磷的情况下，铬欠饱和（5% Cr）和过饱和（14% Cr）对低剂量中子辐照铁铬合金中辐照诱导溶质原子团簇/析出物形成的影响；(2) 辐照温度（290°C与450°C）的影响；(3) 0.06 - 0.6 dpa范围内的中子剂量对低活化F/M 9%Cr钢Eurofer97辐照响应的影响。发现在两个辐照温度下，过饱和的Fe-14Cr-NiSiP中富铬α'相粒子的辐照增强形成是主要效应。相比之下，Fe-5Cr-NiSiP中不可能形成α'相，在0.1 dpa时观察到的明显辐照效应主要归因于添加的镍、硅和磷。最后，Eurofer97在低中子剂量下表现出异常微弱的辐照效应，其原因也进行了探讨。
