Comparative small-angle neutron scattering study of neutron-irradiated Fe, Fe-based alloys and a pressure vessel steel

Structure, energetics and thermodynamics of copper–vacancy clusters in bcc-Fe: An atomistic study

“…Based on the results of the present work and on experimental data obtained by positron annihilation spectroscopy [39] and small-angle neutron scattering [3] it can be assumed that the radiation-enhanced formation of v l Cu m clusters occurs according to the following scenario. Continuous neutron irradiation leads to supersaturation of vacancies and self-interstitials.…”

“…On the other hand, the concentration of Cu in RPV steels is typically 0.05-0.3% which is much higher than its solid solubility at the operating temperature of about 540-560 K. Therefore, the irradiation-enhanced Cu diffusion leads to the formation of nanosized Cu-rich clusters or precipitates. Experimental investigations showed that these nanoclusters may not only consist of pure Cu but also include vacancies [1][2][3][4]. This finding should be a consequence of the vacancy mechanism of Cu diffusion, i.e.…”

Characterization of neutron-irradiated ferritic model alloys and a RPV steel from combined APT, SANS, TEM and PAS analyses

“…The measuring procedure and analysis are described in detail in Ref. [16]. We assumed a dilute two-phase matrix-inclusion microstructure composed of non-magnetic spherical scatterers randomly dispersed in a pure Fe matrix.…”

“…They are individually described in Refs. [15][16][17][18]. The whole set of results is exploited in Section 4 in order to obtain a coherent picture of irradiation damage in the present case and of the effects of dose and of the alloying elements, mainly Cu, Mn and Ni.…”

Kinetic Monte Carlo simulation of nanostructural evolution under post‐irradiation annealing in dilute FeMnNi

“…Combining the two figures we note the existence of two recovery stages, distinguishing between V clusters as seen by PAS (above ~45 vacancies the technique does not distinguish size any more) and voids (> 1 nm in diameter). The threshold of 1 nm was chosen because it corresponds to the lower SANS detection limit in Fe-based alloys [16,17]. There is a first stage at about 400-450 °C, which corresponds to a progressive and significant decrease of the overall defect density, as a consequence of a process of coalescence of small and mobile vacancy clusters, leading to a redistribution of vacancies into fewer and larger defects (still largely < 1 nm in diameter).…”