Residual strain-stress in manganese steel railway-crossing determined by synchrotron and laboratory X-ray

The residual stress within the nose of a worn manganese steel railway crossing was investigated. The macroscopic residual stress at the running surface was determined in areas with and without visual faults by laboratory X-ray. To get information about the penetration depth of the residual stress, synchrotron X-ray diffraction was used to map the distribution of local (within grain) residual strains below the running surface. The laboratory X-ray measurements revealed significant compressive stress on the rail running surface. The synchrotron measurements documented that local strains exist through the entire depth investigated. Relations between residual stress, plastic deformation and crack formation are analyzed leading to discussion on potentials/limitations of the two experimental methods for investigations of residual stress in large engineering components.