STEEL RAIL FOR HIGH SPEED AND QUASI-HIGH SPEED RAILWAYS AND MANUFACTURING METHOD THEREOF

摘要

Disclosed are a steel rail for high speed and quasi-high speed railways and the manufacturing method thereof. The steel rail with better rolling contact fatigue property can be obtained by reducing the percentage of carbon and using a technique of controlled cooling after rolling. The steel rail contains the following chemical compositions by weight: 0.40-0.64% of C; 0.10-1.00% of Si; 0.30-1.50% of Mn; less than or equal to 0.025% of P, less than or equal to 0.025% of S, less than or equal to 0.005% of Al; greater than 0 and less than or equal to 0.05% of a rare earth element; at least one of V, Cr, and Ti, having a total quantity of greater than 0 and less than or equal to 0.20%; and a remaining percentage of Fe and inevitable impurities. The steel rail manufactured according to the method in the present invention maintains the strength and hardness of the steel rail currently used in high speed railways while enhancing the tensile plasticity and yield strength. In addition, the energy value for the initiation and propagation of the fatigue micro crack on the surface of the steel rail is increased, thus improving the rolling contact fatigue property of the steel rail under the same condition. This prolongs the service life of the steel rail and enhances transportation safety.