Pearlitic steel rail with high strength and toughness and producing method thereof

Abstract

A pearlitic steel rail with high strength and toughness and a producing method thereof. The producing method comprises: controlling the following processing conditions in a rolling procedure to produce the pearlitic steel rail with high strength and toughness: initial rolling temperature of 1,120-1,180° C., final rolling temperature of 840-880° C., rail profile reduction in last two rolling passes of 6%-12%; the steel rail is cooled to 600° C. or lower at a cooling rate ≦2.0° C./s after final rolling, and then air-cooled to room temperature; the chemical composition of the steel rail meets the following requirements: C: 0.75%-0.84%, Si: 0.30%-0.80%, Mn: 0.50%-1.50%, V: 0.04%-0.12%, Ti: 0.004%-0.02%, and 0.10%≦V+10Ti≦0.25%, [N]≦30 ppm, P≦0.020%, S≦0.008%, with the remaining content consisting of Fe and inevitable impurities.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to Chinese Application No. 201410443977.0, filed on Sep. 2, 2014, entitled “Pearlitic Steel Rail with High Strength and Toughness and Producing Method Thereof”, which is specifically and entirely incorporated by reference.FIELD OF INVENTION[0002]The present invention relates to a steel rail, in particular to a pearlitic steel rail with high strength and toughness and a producing method thereof.BACKGROUND OF THE INVENTION[0003]The rapid development of railroads has raised higher requirements for the service performance of steel rails. Especially, for heavy-duty railroads with high traffic volume and high axle load, the early replacement of steel rails as a consequence of quick wearing has become a major factor that has impacts on the efficiency of railroad transportation. Usually, alloying, heat treatment or a combination of them is utilized in the production of steel rails, in order to improve the overall ...