A HYPOTHESIS ON THE ELECTROMAGNETIC CAUSE OF WHITE ETCHING CRACKS IN BEARING STEEL

Initially, a hypothesis on the electromagnetic (EM) initiation of white etching cracks (WEC) in martensitic bearing steel E52100 was presented last year (Scepanskis et al., STLE 2014). The hypothesis pointed out inhomogeneities of the microstructure of the steel like electrically non-conductive cementite particles. The thermal expansion of the non-homogeneous structure, which is caused by electric current, leads to significant localized stresses and micro-deformations that can be associated with WEC formation deep from the surface of the bearing race. Now the model was extended to describe bainitic steel, and the localized stresses are found to be even stronger there. The model, which includes all primary and secondary EM effects including the crucial magnetomechanical phenomenon, will be presented.

AUTHORS

Mihals Scepanski, Andres Jakovics, University of Latvia, Riga, Latvia, Imants Kaldre, Institute of Physics of University of Latvia, Salaspils, Latvia, Walter Holweger, Schaeffler Technologies AG & Co. KG, Herzogenaurach, Germany and Bernard Nacke, Leibniz University of Hanover, Institute of Electrotechnology, Germany