Impact of Tensile and Compressive Stress on Classical and Acoustic Barkhausen Effects in Grain-Oriented Electrical Steel

In this paper, we present the results of the investigation of impact of tensile and compressive stress on the classical Barkhausen effect, magnetoacoustic emission (MAE) signal properties, and B(H) hysteresis loops for grain-oriented (GO) electrical steel. Samples have been glued to a nonmagnetic steel bar and stressed within elastic range (±800 μdef) by means of four-point bending method. The samples were cut out in two directions (parallel - RD and transversal - TD to the rolling direction). The intensities of the Barkhausen effect and MAE are given by root-mean-square voltage envelopes. There were also calculated and compared integrals of those envelopes calculated for one period of magnetization. Tensile and compressive stresses lead to the specific and nonmonotonic evolution of the envelopes of both signals and their integrals. Qualitative discussion of these features leads to the conclusion that complementary study of both effects allows for a nondestructive, quick inspection of stress state of GO electrical steel sheets.