Dislocation core reconstruction induced by carbon segregation in bcc iron

Abstract

Dislocations are central to the understanding of plasticity in metals. Using density functional theory the authors show that interstitial carbon atoms in ferritic steels stabilize a dislocation core configuration called a hard core which is otherwise unstable. Since, as they also show, at equilibrium all dislocations are expected to be fully decorated by carbon atoms, this has important implications for the understanding of plasticity in ferritic steels. It is expected that the picture developed here could also be applicable to other solutes besides carbon and to other metals besides iron.