S. A. Starikov, A. R. Kuznetsov, Yu. N. Gornostyrev, V. V. Sagaradze
DEFORMATION-INDUCED SEGREGATION IN AUSTENITIC ALLOYS
This article covers an overview of recent works devoted to the theoretical study of deformation-induced segregation in austenitic alloys as an example. A theoretical model describing non-equilibrium strain-induced segregation in a ternary alloy during severe plastic deformation is discussed. The model accounts for the generation of point defects, their annihilation at the sinks (such as grain boundaries), as well as mutual recombination. Based on the proposed model, the redistribution of the atoms of the alloying elements and the formation of grain boundary segregations during severe plastic deformation are investigated on the example of the Fe-12Cr-30Ni austenitic alloy. It is shown by the molecular dynamics method that in the Fe-30Ni binary alloy nickel atoms do not have their own thermodynamic incentives for segregation to the grain boundaries. The calculations demonstrate that the main contribution to the formation of segregations is due to the non-equilibrium flows of point defects (vacancies and internode atoms), which develop during severe plastic deformation. The obtained results explain the features of the formation of segregations in the Fe-Cr-Ni alloy during severe plastic deformation.
Keywords: severe plastic deformation, grain boundary, deformation-induced segregation, austenitic alloy.