The effect of DC magnetic field on signal characteristics of magnetic Barkhausen noise

Magnetic Barkhausen Noise (MBN) detection technology shows great potential in the pipeline detection of stress, microstructure, and fatigue damage. However, in actual application, some pipes such as those near power plant are exposed to external magnetic fields or contain remanence. The presence of these magnetic fields will affect MBN features and then influence the testing results. To investigate the effect of DC magnetic field on MBN signal characteristics, theoretical analysis and experimental verification were carried out in this paper. It is found that the intensity and direction of the DC magnetic field have great effects on MBN signal characteristics, including the changes in the energy of MBN signal, the peak position and the shape of MBN signal profile.