Application of eddy currents to the inspection of fatigue-corroded railway axles

Recent experience with existing railway axles indicates that even when they are operated within the design loads, failure can happen due to the synergetic effect of both corrosion and cyclic loads. This synergy is not yet thoroughly understood, however a need for detecting corrosion-fatigue during service is mandatory. In the present paper, corrosion-fatigue tests are carried out, in the lab, on small-scale specimens in order to investigate the possibility to apply eddy currents non-destructive inspection to the detection of corrosion pits and corrosion-fatigue cracks during the service of railway axles. The obtained results are also supported by suitable numerical simulations carried out by a dedicated software package. Part of the presented results were obtained in the frame of the international research project RSSB T728 (just concluded) and the European research project WOLAXIM (still in progress).