Barkhausen noise evaluation of fatigue in high strength steel

Abstract

The rms value of Barkhausen noise and residual stresses were followed as a function of the number of loading cycles in alternating bending fatigue of high strength steel. The measurements were carried out in several directions to ensure that changes in the angular anisotropy of Barkhausen noise could be detected. The Barkhausen noise amplitude in the loading direction changed only slightly due to cyclic deformation. On the other hand, in other directions, especially in the angle 60 with respect to the loading direction, significant alteration of Barkhausen noise amplitude as a function of the number of loading cycles was observed. The angular anisotropy of Barkhausen noise increased as a function of the number of loading cycles. The amount of increase depended on the strain amplitude. The changes in the Barkhausen noise amplitude could not be explained solely on the basis of changes in residual stresses.