Microstructural characterization of irradiation-induced Cu-enriched clusters in reactor pressure vessel steels

Hardening and microstructural evolution in A533B steels under high-dose electron irradiation

“…Regarding microstructures, the present experiments confirmed that well-defined Cu-rich precipitates, which have a shell structure, Fe-Cu core and Mn-Ni-Si-rich shell, were formed under electron irradiation at 290°C in medium Cu commercial steels. The structure and composition of the precipitates were basically the same as those observed in commercial steels irradiated with neutrons [21,25,[28][29][30][31]. The result that no micorvoid formation occurs under electron irradiation at 290°C is also consistent with the reported results for commercial steels after neutron irradiation at near 300°C [32][33][34].…”

“…11, together with literature data from commercial steels containing higher Cu (0.15-0.5%) irradiated with neutrons [28,[35][36][37][38]. Since the literature data were obtained from high Cu steels at relatively low doses (less than 30 m dpa), it is reasonable to assume that the Cu-rich precipitate is the dominant source.…”

“…The dose rate of the electron irradiation was 3 to 4 times higher than that of the MTR irradiation and two orders higher than that of the PWR irradiation. The dose rate effects on Cu-rich precipitates under neutron irradiation have been reported [1,[25][26][27][28], in that neutron irradiation at a higher dose rate produces Cu-rich precipitate with smaller diameter and higher density. From the data for neutron-irradiated steel A in Table 3, higher-dose-rate MTR irradiation gave a smaller diameter than PWR irradiation even though the dose was higher for MTR irradiation.…”

Irradiation-Induced Solute Clustering in a Low Nickel FeMnNi Ferritic Alloy

“…This embrittlement is partly due to the formation of a high number density of nanometer-sized solute clusters, which impede the motion of dislocations. They are mainly enriched in Cu, Mn, Ni and Si [2][3][4][5][6][7][8][9]. To be able to predict the evolution of the mechanical properties of RPV steels, it is necessary to understand their formation mechanism.…”

Study of atomic clusters in neutron irradiated reactor pressure vessel surveillance samples by extended X-ray absorption fine structure spectroscopy

“…Cu, Ni, Mn, P, Si etc.) to irradiation hardening and embrittlement have been studied intensively [6][7][8]. Besides neutron irradiation also thermal influences affect the embrittlement of the vessel steel [5].…”