Study on Contact Fatigue Damage of Steel Rail

A test method of rail's contact fatigue is developed,which is different from the conventional test method and much similar to the true contact conditions on the practical rails.The simulated test for the anticontact-fatigue property of different kinds of rails is carried out,in which the velocity is 160 km/h,the radius is 800m,and the axle weight is 25t.The results indicate that the contact fatigue damage is relatively slight for the rail which has slow crack initiation and expansion ratio and large wearing-away in the given test conditions (work condition).The contact fatigue damage of U75V hot-roll rail with 1 000 MPa strength level is the most serious in all kinds of the tested rails.According to the features of contact fatigue damage,the heat -treated rail with 1300 MPa strength level should be used on the small radius or the heavy-duty line,and the rail with slow crack expansion ratio should be used on the high speed or fast line.