Interaction between cracks and microstructure in three dimensions for rolling contact fatigue in railway rails
Artikel i vetenskaplig tidskrift, 2014

The rail–wheel contact generates plastic deformation and cracks in the top layer of a rail. Rolling contact fatigue (RCF) cracks in rail samples from track and from a full scale test rig were examined. Due to the shear forces arising in the wheel rail contact, the microstructure close to the surface becomes aligned in the shear direction. Thereby, the pearlite becomes anisotropic, and resistance to cracks is lower in certain directions. RCF cracks follow the weakest direction of the microstructure, which in pearlitic railway rails is the aligned pearlite structure or singular weaknesses such as pro-eutectoid ferrites or slags. The deformation of the microstructure is different depending on loading situation and original microstructure (rail grade). Once the plastic deformation is present, the cracks follow the path of the weakest crack resistance. Cracks close to each other can interact or shield each other; it is unclear, however, to what extent. In this paper, a new method is described that allows the presentation of RCF cracks in three dimensions.

Författare

Martin Schilke

Chalmers, Material- och tillverkningsteknik, Materialteknologi

NASIM LARIJANI

Chalmers, Tillämpad mekanik, Material- och beräkningsmekanik

Christer Persson

Chalmers, Material- och tillverkningsteknik, Materialteknologi

Fatigue and Fracture of Engineering Materials and Structures

8756-758X (ISSN) 1460-2695 (eISSN)

Vol. 37 3 280-289

Ämneskategorier

Maskinteknik

Metallurgi och metalliska material

Styrkeområden

Transport

Materialvetenskap

DOI

10.1111/ffe.12112