The influence of stress on surface Barkhausen noise generation in pipeline steels

Surface Barkhausen noise (SBN) generation has been monitored for two different sweep-field orientations in a pipeline half-section that was subjected to circumferential tensile and compressive stresses. When the sweep field was oriented in the circumferential direction, the SBN increased with applied tension and decreased with compression. The SBN signal was more sensitive to tension than to compression. This is explained in terms of a preferred axial domain orientation. Unlike the case of a circumferential magnetic sweep field, neither tension nor comparison had a significant effect on the SBN signal when the field was oriented axially