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

The process of nickel segregation at grain boundaries in the Fe-Cr-Ni alloy upon severe plastic deformation has been investigated depending on the temperature. The kinetics of the formation of segregates has been studied by numerically solving diffusion equations that take into account the generation and absorption of point defects and their mutual recombination. It has been shown that the Ni concentration at grain boundaries is reduced with increasing temperature and at T ≥ 600 K no segregates are formed, which agrees with the experiment. The dependence of the degree of Ni segregation on the rate of generation of point defects is nonmonotonic, with a maximum in the range of medium rates of generation, which qualitatively corresponds to the analogous dependence observed upon radiation-induced segregation of nickel in this alloy.