ESTIMATION OF GROWTH IN ROLLING CONTACT FATIGUE DAMAGE TO RAIL STEEL WITH DEVELOPMENT TEXTURE

Rolling contact fatigue tests are performed using cylindrical test pieces taken out of rail, under conditions of slip ratio 0%, maximum Hertz pressure 1.2 GPa, velocity 60 km/h and water lubrication. The behavior of plastic deformation of crystal is accelerated further when fatigue progresses after a number of cycles larger than a specific value and then so called shelling grows with a remarkable development of the texture in either test pieces corresponding to the rail or the wheel. The results indicate that the dislocation density increases, while a preferred orientation texture and a cell structure emerge in the contact surface layer with an increase in the number of cycles of rolling contact fatigue. And these correspond to the development of texture.