Micromechanics behavior of fatigue cracks in Hadfield steel railway crossing

In order to predict the mechanism of the formation and propagation of rolling contact fatigue cracks in Hadfield steel railway crossings （HSRC）, the residual strain, microstructure, crystal orientation, and microhardness surrounding fatigue cracks were investigated. Results show that the formation and propagation of fatigue cracks in HSRC have no correlation with the crystal orientation and boundaries of grains. The hardness and residual strain in the field around the fatigue crack are lower than those in other regions. The compressive strain around the fatigue crack is released after crack propagates, which reduces the hardness around the fatigue crack. Deformation twins and dislocations play a key role in the work hardening of HSRC.