Rolling Contact Fatigue (RCF) crack initiation is often connected to the accumulation of plastic deformation in the surface layer of rail and wheel. The behaviour and strength of this highly deformed layer are thus key properties of a rail or wheel material. Microhardness and 3D head check crack geometry analyses of the surface layer of a rail (from field) were conducted in project MU24 and the modelling of anisotropic evolution and response of highly deformed pearlitic steel was developed in project MU19. The modelling was validated against wire-drawing results from the literature as well as high-pressure torsion tests and micropillar tests performed at Erich Schmid Institute in Leoben (Austria). A new biaxial tension and torsion testing machine at the Department of Materials and Manufacturing Technology (now Industrial and Materials Science) will make it possible to perform laboratory tests on rail and wheel materials in more realistic loading conditions than earlier. Aims of the current project are (1) to find ways to produce anisotropy (by predeformation) of the rail material similar to what is found in rails in field, (2) to determine the multiaxial cyclic behaviour of rail steel in the biaxial testing machine, (3) to utilize and further develop cyclic material models from, e g, project MU19, that take anisotropy into account, and (4) to analyse crack initiation and formulate crack initiation criteria. The ultimate goal is to increase the understanding of the role of the microstructure development in different rail materials subjected to realistic traffic loading conditions.
This is a doctoral project. Mr Knut Andreas Meyer (now doctor) is the doctoral student and Professor Magnus Ekh the project leader and supervisor. Professor Johan Ahlström is assistant supervisor. Knut Andreas Meyer successfully defended his doctoral dissertation on 4 October 2019 and continues as researcher in the project.
- SweMaint AB (Private, Sweden)
- Faiveley Transport Nordic AB (Public, Sweden)
- Lucchini Sweden AB (Private, Sweden)
- SJ AB (Public, Sweden)
- Abetong AB (Private, Sweden)
- Atkins Sverige AB (Private, Sverige)
- Swedish Transport Administration (Public, Sweden)
- voestalpine VAE GmbH (Private, Austria)
- Bombardier Transportation GmbH (Private, Germany)
- voestalpine Schienen GmbH (Private, Austria)
- Green Cargo AB (Public, Sweden)
The project is closed: 15/05/2020