The dynamics of an edge dislocation in a medium with random oxide dispersoid particles acting as pinning centres was analysed. The dislocation line undergoes a de-pinning transition, where the order parameter was the dislocation line velocity v, which increased from zero for driving external resolved shear stresses τ beyond to a threshold value τc, known as the critical resolved shear stress. The critical stress was obtained by means of statistical analysis of the motion of a single dislocation in its glide plane, using over-damped, discrete dislocation dynamics simulations.

Depinning Transition of a Dislocation Line in Ferritic Oxide Strengthened Steels. B.Bakó, M.Zaiser, D.Weygand, M.Samaras, W.Hoffelner: Journal of Nuclear Materials, 2009, 385[2], 284-7