Influence of the temperature and rate of generation of point defects on the processes of deformation-induced segregation in the Fe-Cr-Ni alloy

Formation of grain boundary segregations in alloy Fe-Cr-Ni during strong deformation and under radiation

“…An increase in the deformation temperature leads not only to an acceleration of deformation, but in addition to a decrease in the density of screw dislocations that gener ate point defects [14]. Therefore, the DIS takes place in a relatively narrow temperature range (T < 400 K).…”

“…Hence, it should be expected that the kinetics of the formation of DIS and RIS can be similar. An essential difference between the DIS and RIS is in the fact that with increasing temperature, the intensity of the DIS decreases up to the complete disappearance of the effect because of he decrease in the density of disloca tions generating point defects [14,17]. Hence, it is unclear whether the mode of the "rapid" DIS will be realized under conditions of intense deformation which usually is realized at lower temperatures in comparison with those employed for irradiation.…”

“…As in previous studies [12][13][14], in order to simulate the processes of RIS and DIS we applied the model described earlier in [13,18]. A three component alloy Fe-Cr-Ni was considered subjected to severe plastic deformation or radiation.…”

“…The values of the parameters used for the computations are given in [12,13,19]. In the adopted model of severe plastic deformation, it was assumed, as previously [12][13][14], that at the achieved stage of deformation developed there exist fine grains which do not undergo further division. Therefore, the grain size did not vary in the computations and was set to be 200 nm.…”

“…In [12][13][14] it has been shown by numerical simula tions of the deformation induced segregation (DIS) that in the Fe-Cr-Ni alloy the GB is enriched in nickel and is depleted of other components. The results obtained agree well with the available experi mental data [15,16] for the Fe-Cr-Ni alloy and made it possible to conclude that the development of the DIS can be described using the same concepts as for the RIS, taking into account the difference in the mechanisms of generation of point defects.…”