Atomic-level simulations, based on the embedded atom method, were used to describe the energetics of a H atom during interaction with a moving edge dislocation in a body-centered cubic Fe crystal. In the chosen framework, it was found that an H atom occupying a site in the Fe lattice could block the movement of an edge dislocation and that the stress exerted on the dislocation could reach a maximum value of 15.5MPa. However, it was also found that an interstitial H atom did not impede the movement of the dislocation and exerted a maximum stress of 38.2MPa at the moment when the moving dislocation passed. These findings were correlated with the macroscopically observed mechanical behavior of H-charged Fe, which showed that H could cause an increase in the flow stress and/or local plasticity enhancement.

Molecular Dynamics Simulation of Hydrogen-Edge Dislocation Interaction in BCC Iron. S.Nedelcu, P.Kizler: Physica Status Solidi A, 2002, 193[1], 26-34