In order to clarify the mechanism of initiation of rolling contact fatigue cracking, so called shelling, on the running surface of rails in railway track, the characteristics of the deformed rail surface layer have been investigated by means of electron microscopes (SEM, TEM) and X-ray apparatus comparing the rolling-contacted test pieces and cold-rolled test pieces. A texture is formed as a result of the simple slip deformation of crystals in the deformed surface layer of rails used in track and the rolling contact fatigue-tested rails. This texture disappeared at the topmost surface because of the occurence of some random plastic deformation. On the contrary, the texture of the cold-rolled test pieces results from the complex slip deformation of crystals and does not disappear at the surface.
