High-carbon and high-strength and toughness pearlitic rail and manufacturing method thereof

Abstract

In view of the problem of uneven performance of railhead sections of pearlitic rail manufactured with existing technique and the poor performance of the pearlitic rail obtained, the invention provides a manufacturing method for high-carbon and high-strength and toughness pearlitic rail, including the following steps to: a. hot roll the steel billet into rail, with a final rolling temperature of 900-1000° C.; b. blow a cooling medium to the top surface of railhead, wherein, the two sides of railhead and the lower jaws on two sides of railhead when the center of top surface of rail is air-cooled to 800-850° C.; then air-cool the rail to room temperature after the center of top surface of rail is cooled to 480-530° C. By controlling the composition of steel and adopting a two-stage accelerated cooling, a high-carbon rail is produced with better strength and excellent toughness which is suitable for heavy-haul railway.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority from CN 201710934583.9 filed Oct. 10, 2017, the contents of which are incorporated by reference in their entireties.FIELD OF INVENTION[0002]The invention relates to a rail, particularly to a high-carbon and high-strength and toughness pearlitic rail and the manufacturing method thereof.BACKGROUND OF THE INVENTION[0003]The rapid development of railway has higher requirements for the service performance of rail. With the continuous improvement of China's high-speed railway network, heavy-haul transformation will be conducted gradually for the existing main railway lines with passenger and freight mixed traffic. And the heavy-haul railway will develop towards large volume, high axle load and high density. As a key component of railway, the quality and performance of rail are closely related to the transport efficiency of railway and the safety of traffic. With the improvement of the transportation capacity of...

AI Technical Summary

Benefits of technology

The invention describes a manufacturing method for a high-carbon and high-strength and toughness pearlitic rail that has better strength, hardness, toughness, and plasticity compared to existing methods. The method uses a specific composition rail and a two-stage accelerated cooling method. The resulting rail has a limited content of C within the range of 0.86%- 1.05% to ensure optimal strength and toughness. The method is easy to conduct and requires low equipment requirements. The high-carbon and high-strength and toughness pearlitic rail can enhance the overall strength and toughness of the railhead and prolong the service life of the rail under the same conditions.

Problems solved by technology

The technical problem to be solved by the invention is that: in prior art, the methods adopting different cooling rates in different temperature ranges are used for the heat treatment of rail, therefore the pearlitic rail obtained has poor performance.