Atomistic simulations in the Fe–C system

We improved an embedded atom (EAM) interatomic potential for the description of defective body-centered cubic α-Fe containing C interstitials. Guided by first principles calculations results the potential was developed to reproduce experimental information such as the dilute heat of solution of carbon, the vacancy-carbon binding energy and its configuration, the location of interstitial carbon atoms and the migration energy of carbon atoms in body-centered cubic (bcc) Fe. The potential reproduces the known physical properties of carbon as an interstitial solute element both in ferrite and austenite. It also successfully calculates energetically favored defect configurations and predicts the formation energy and configurations of multicarbon-vacancy defect clusters. The potential performs well for the atomistic study of the interactions between carbon interstitial solute atoms and extended defects in ferrite, such as free surfaces, dislocations and grain boundaries. Since C–C interactions are taken into account, this potential is applicable to the study of cementite and we present results for a ferrite/cementite interface.