Creep mechanisms in oxide-dispersion-strengthened alloys

摘要

Analyses of the creep properties of oxide-dispersion-strengthened (ODS) alloys in relation to the creep characteristics observed for prestrained nickel suggest that the principal role of dispersoid particles is to stabilize the retained dislocation substructures present after thermomechanical processing. On this basis, straight-forward explanations can be provided not only for the depdnedence of creep strength on grain size and shape but also for the pronounced creep anisotropy of ODS alloys with high grain aspect ratios. Furthermore, even the complex power-law behavior patterns displayed by commercial ODS ferritic steels can then be predicted and explained using the #theta# relationships which quantify creep curve shapes.