Electrical-resistance-based fatigue damage evaluation in full-forward rod extruded 16MnCrS5

The fatigue capability of components is considerably affected, among others, by the occurrence of forming-induced damage. Understanding how forming-induced damage affects the fatigue behavior allows for optimized component design that enhances service performance and promotes lightweight construction. Electrical resistance measurements offer the opportunity for a non-destructive fatigue damage assessment. In contrast to common ex-situ measurements, in-situ measurements provide the advantage of continuous acquisition, but also require complex compensation of influences. Therefore, the fatigue damage evolution was determined through a coupled measurement setup on the basis of the electrical resistance. The resistance was measured with a self-developed in-situ experimental setup combined with the strain, diameter and temperature. This allows a compensation of geometrical and thermal influences on the electrical resistance, so that microstructural changes under fatigue loading can be evaluated. Additionally, the individual influences of geometry and temperature on the electrical resistance were quantified and compared with the measured electrical resistance change.