The Influence of Cyclic Stressing on the Barkhausen Effect in Polycrystalline Iron

ABSTRACT The Barkhausen magnetic noise signals caused by the irreversible, jerky motion of magnetic domain walls through the different dislocation arrangements due to cycling with constant applied stress amplitudes were measured in polycrystalline iron and a low carbon structural steel. The changes in the pulse distribution as a function of stress cycling were found to depend on the magnitude of the applied stress amplitude. The changes were pronounced at amplitudes corresponding to short fatigue lives. At stress amplitudes close to or below the fatigue limit, the changes were small or negligible. This suggests that magnetic measurements based on Barkhausen signals might possibly be used as a non-destructive way to determine fatigue strength and fatigue life in structural steels.