Barkhausen Noise in 100Cr6 Bearing Steel as a Function of Microstructure and Stress State

This study is focused on the unwrapping contribution of microstructure (mainly expressed in terms of dislocation density) and stress state in the quenched bearing steel 100Cr6. Microstructure as well as residual stress state alterations are developed only as a function of variable infeed rates in the flat plunge grinding (other grinding conditions are kept constant). The study is also dealing with the synergistic contribution of residual stress state and the superimposing elastic external stress developed during bending. It was found that the Barkhausen noise after grinding is mostly a function of the thermal softening, whereas the role of residual stress state is only minor. The growing Barkhausen noise emission at the lower infeed rates is connected with the compressive stress, and the tensile stresses are developed at the higher removal rates only. The study also demonstrates good sensitivity of Barkhausen noise when this emission is descending along the compressive external stresses and the ascending evolution along the tensile stresses when the magnetic field is altering along the direction of exerted stress. On the other hand, this evolution is reversed when the altering magnetic field is altered along the transversal direction.