Correlation between surface integrity of ground medium carbon steel with Barkhausen Noise parameters and magnetic hysteresis loop characteristics

An experimental investigation was carried out to study the effect of stresses that approach and exceed the yield point, on the magnetic properties of ground samples of medium carbon steel upon surface grinding. The observed magnetic behaviour included magnetic Barkhausen emission measurements, characteristics changes in the shape of hysteresis loop and magnetic properties derived from hysteresis loop. Relation between Barkhausen Noise (BN) parameters and other magnetic properties with stress have been discussed in term of degree of plastic deformation. It was observed that peak of BN signal, saturation magnetization and permeability derived from hysteresis loop depend to some extent on residual stress and degree of plastic deformation while other magnetic properties obtained from BN profile and hysteresis loop are stress insensitive. X-ray diffraction (XRD), metallographic study and microhardness measurement of ground samples have been undertaken to confirm the results obtained by analysis of magnetic parameters.