The effect of composition variations on the response of steels subjected to high fluence neutron irradiation

Atom probe characterisation of segregation driven Cu and Mn–Ni–Si co-precipitation in neutron irradiated T91 tempered-martensitic steel

“…MNSPs also develop in low Cu steels, although even trace amounts of Cu are known to be potent catalysts for their formation [53]. The first experimental proof of MNSP formation in irradiated RPV steels was reported in 2004 [54]; and, since then, MNSPs have been widely observed [16,47,50,51,[55][56][57][58]. Notably, CRPs and MNSPs are well predicted by thermodynamic and kinetic modelling [45,46,59].…”

“…Partial edge clusters (defined as a cluster from the original material whose true extent is not completely contained within the reconstructed APT volume) were removed from the cluster search to avoid underestimation of the sizes. The algorithm used to detect and remove the edge clusters was developed by Jenkins et al (2020) [58,69]. The number density of clusters, N !…”

“…The situation in APT is further complicated by trajectory aberrations that affect the spatial resolution of the reconstructed atom maps, as discussed by Larson et al [72], which can erroneously introduce Fe from the surrounding matrix into the defined MNSP cluster. Therefore, in this study, all cluster compositions did include the peak at 29, identifying this as 58 Ni 2+ (not 29 Si 1+ as it did not match the expected natural isotope ratios) and the Fe ions will be removed from the cluster calculation, which is similar to previous studies [53,58,71]. For an additional check, the spatial distribution of ions within the reconstructed data associated to the 29 Da was visually inspected and observed to correspond to the locations of MNSPs, further indicating that the majority of 29 Da peak was attributed to 58 Ni 2+ .…”

Direct Observation of PFIB-Induced Clustering in Precipitation-Strengthened Al Alloys by Atom Probe Tomography

“…where N is the number of clusters, ρ th is the theoretical density of the cluster (taken to be the same as the atomic density of Al), η is the detection efficiency of the LEAP 5000XS (80%), and N total is the total number of ions in the dataset (Jenkins et al, 2020).…”

Nanocluster evolution and mechanical properties of ion irradiated T91 ferritic-martensitic steel

“…Thus, the overlap at 29 Da could potentially be incorporated within MNSPs. In this work, all cluster compositions include the 29 Da peak and are labelled as 58 Ni 2+ (and not 29 Si 1+ as the isotopic ratios for neighbouring peaks did not match natural levels), and this method has been used in previous studies [33,64,65]. Fe ions are also removed from all cluster calculations based on previous methods [64,65].…”