The research was performed for polycrystalline aluminum by steady-state creep. It is known that at the macro-scale level, deformation exhibits localized behavior. The localization patterns would propagate over the deforming sample by steady-state creep, forming thereby a kind of phase autowave. The rate of phase autowave increases with the growing extent of straining. It is demonstrated that the processes controlling the autowave rate have the same activation volume as the processes controlling the creep rate.