Microstructural changes in a neutron-irradiated Fe–6 at.%Cr alloy

Abstract

The microstructural and chemical changes in a Fe-6 at.% Cr binary model alloy neutron irradiated to 1.82 dpa at 290 o C were investigated using atom probe tomography. After irradiation, Si and Cr are found segregated to dislocation loops, which were analyzed in terms of number density, size, and habit plane. Grain boundary chemistry was quantitatively compared between the as-received and the neutron irradiated alloys. The results are discussed in the context of equilibrium segregation, radiation-enhanced diffusion, and/or radiation induced segregation.

On the role of Ni, Si and P on the nanostructural evolution of FeCr alloys under irradiation

“…However it is worth noting that the measured Cr concentration is systematically 2% over the nominal one. This is coherent with Cr interstitial dragging mechanism and with experimental observations of Cr enrichment in SRCs under neutron irradiation [25] and Cr segregation at dislocation loops [11,31]. It must be emphasised that Cr-enriched clusters, which are not linked to SRCs, are observed at 0.5 dpa in agreement with the work of Tissot et al [39].…”

Radiation tolerance of neutron-irradiated model Fe–Cr–Al alloys

“…The presence of α' after irradiation in this study is consistent with previous work on irradiated Fe-Cr and thermally aged Fe-Cr-Al alloys. Bachhav et al [32,59,60] investigated a series of model Fe-Cr alloys irradiated to 1.82 dpa at 290°C using atom probe tomography. That study showed precipitation of α' to be linearly dependent on chromium composition, with an upper limit in number density near 5.3×10 24 m -3 in the Fe-18Cr specimen, a result remarkably similar to the result here for the Fe-Cr-Al systems studied (see Table 3).…”

Application of STEM characterization for investigating radiation effects in BCC Fe-based alloys

“…Three-dimensional atom probe tomography using a local electrode atom probe tomography (LEAP) measures RIS profiles with higher spatial resolution, and therefore a lesser convolution effect. Thus, LEAP measurements of RIS in BCC F/M alloys [19][20][21][22][23] typically exhibit enhanced spatial resolution and larger RIS magnitudes than those measured by STEM-EDX in this work.…”