Damage structures and precipitation in electron-irradiated iron-chromium alloys

Dislocation driven chromium precipitation in Fe-9Cr binary alloy: a positron lifetime study

“…But precipitates like contrast is observed uniformly throughout the sample, particularly dense along the grain boundaries. These contrast features seen in TEM at this temperature is due to Cr rich precipitates, similar to the observation of electron irradiated studies 10 . The observed increase in lifetime beyond 823 K (Fig-1a) can be understood in terms of these Cr precipitates.…”

“…Another interesting finding related to dependence of initial micrstructure is, Wakai et al 35 used furnace cooled samples, expected to be coarse grained structure without dislocations, for irradiation and observed depletion of Cr at grain boundaries. Ezava et al 10 used cold rolled 60 µm thick samples for irradiation and observed Cr enrichment at grain boundaries at 873 K. In the later case recrystallization of the deformed structure, to subgrain structure, is expected at this temperature. Heishichiro et al 36 also showed depletion of Cr at grain boundaries but not reported the initial state of the sample.…”

“…Positron annihilation studies have also showed accelerated phase separation upon electron irradiation followed by isochronal annealing below 700 K for wide range of Cr concentrations (5-20 wt%) 8,9 . Electron microscopy and Energy dispersive X-ray spectroscopy studies showed clustering of Cr with insitu electron irradiation at 873 K for Fe-2.8at%Cr 10 . Helium implantation causing Cr segregation at grain boundaries was also reported 11 .…”

Segregation of Cr at tilt grain boundaries in Fe–Cr alloys: A Metropolis Monte Carlo study

“…Experiments involving irradiation in Fe-13Cr [7] and Fe-10Cr [8] alloys show that Cr depletion takes place after electron irradiation at 400°and 500°C, respectively. Whereas, in Fe-2.8Cr, a strong enrichment was observed under electron irradiation at 600°C [9]. Finally, neither enrichment nor depletion of Cr was seen in Fe-5Cr alloy irradiated at 400°C [7].…”

Atomistic modeling of nanosized Cr precipitate contribution to hardening in an Fe–Cr alloy

“…During neutron irradiation, it is known that fine (2-30 nm in diameter) bcc Cr-rich precipitates (a 0 ) are formed in high Cr steels, in addition to clusters of vacancies and self-interstitial defects [2][3][4][5][6][7]. Little and Stow [2] used transmission electron microscopy (TEM) to characterize the critical Cr content for the formation of a 0 precipitates as about 10 wt.% in low carbon steels under irradiation.…”