Studies of the contribution of alternating electromagnetic fields toward material fatigue in 100Cr6

Purpose - The purpose of this paper is to show how controlled exposure of electromagnetic fields toward bearing steel vulnerates the microstructure. The ability of Barkhausen Noise signal processing is used for detecting phenomena Such as dislocation and subgrain formation processes as the beginning of later failures. Design/methodology/approach - A Barkhausen noise signal measurement equipnient is used for detecting subsurface distress of 100Cr6 as a function of the applied electromagnetic and mechanical stress. Barkhausen noise signal is mathematically processed by use of fractal dimension analysis. Findings - The paper cleary reveals significant impact of electromagnetic field in junction with mechanical loading. Electromagnetic impact depends on the magnitude of the field. Research limitations/implications - Research limitations are given by the fact that in real field applications, e.g. wind power plants, bearings are exposed by multiple influences and the methodology is not applicable to those conditions. Practical implications - The methodology can be applied to real field applications in condition monitoring systems. Up to now, no reasonable on-line measurement is in use determining sub surface fatigue phenomena. The paper hence, reveals the possibility to raise condition monitoring into a new perspective. Originality/value - The use of Barkhausen noise signal processing, as presented here, is original with respect to real field applications, such as wind power plants with a high demand in condition monitoring, especially off-shore plants