Quantitative fatigue fracture surface analysis on railway axles

A Ratier (1) , P Feraud (1) , F. Chalon (2) , P Lallet , Narayanaswami Ranganathan (2)

1 SNCF-AEF
2 LMR - Laboratoire de Mécanique et de Rhéologie

For passengers' safety and to improve railway axles maintenance, the French railway company, SNCF, studies the evolution of crack length in function of time in fatigue loading situations. To achieve this, it's necessary to know the in-service axle loading. As in-service measurements are very expensive and specific, authors decided to study fracture surfaces of components cracked or broken in service. So, the question is: how can we determine the loading history of a cracked component studying the fracture surfaces? This amounts to determining fracture mechanics parameters such as the maximum stress intensity factor Kmax along the crack path. Authors have ever transferred a quantitative fractographic analysis method from aluminium alloys to axle steel EA4T. This method is based on quantification of significant fractographic features such as striations. But, due to limits of this one, authors decided to add another technique based on X-ray diffraction measurements. In this paper, results of these methods are highlighted and discussed .

Mots clés: Railway axles; loading history; quantitative fractography; XRD

Domaines: Mécanique des matériaux [physics.class-ph]

A Ratier, P Feraud, F. Chalon, P Lallet, Narayanaswami Ranganathan. Quantitative fatigue fracture surface analysis on railway axles. 18th International Wheelset Congress, Nov 2016, Chendu, China. ⟨hal-01689628⟩