Micro-mechanism of rolling contact fatigue in Hadfield steel crossing

The formation of the fatigue cracks was due to massive vacancy clusters in the subsurface layer of Hadfield steel crossing, which are induced by the accumulated plastic deformation under the conditions of impact and contact stresses from train wheels. The high concentration layers of vacancy clusters were formed parallel to the working surface of the crossing, which caused the initial rolling contact fatigue cracks to be parallel to the working surface with a laminar distribution in the depth direction. It can be predicted that metals containing elements with larger atomic diameter should have better rolling contact fatigue and wear performances.

► Plastic deformation is caused by rolling contact stress on Hadfield steel crossing.
► Accumulated plastic deformation induced massive vacancy clusters.
► Massive vacancy clusters in worn surface of crossing induced the fatigue cracks.
► Metal with bigger atomic radius maybe has better rolling contact fatigue performance.