Nondestructive Magnetic Monitoring of Grinding Damage

This paper deals with investigation of surface damage induced by grinding operation on the rings made of 100Cr6 bearing steel of hardness 62HRC. Progressively developed grinding wheel wear is caused by using the series of identical rings while the surface properties of machined rings like a hardness, residual stresses, microstructure alterations and magnetic Barkhausen noise (BN) emissions are monitored as manifestations of increased thermal damage. The noninvasive observations based on the BN emissions are performed on each ring while more laborious experimental techniques are used on selected rings. The presented results also indicate that properly suggested monitoring system based on BN emissions can reliably detect surface burn induced by thermal damage of ground surface.