Marine environment corrosion-resistant steel rail

Abstract

The invention relates to a steel rail material, and in particular relates to a marine environment corrosion-resistant steel rail. The technical problem to be solved by the invention is to provide a marine environment corrosion-resistant steel rail. The marine environment corrosion-resistant steel rail is prepared by adopting a heat treatment method comprising the following steps: performing accelerated cooling on the steel rail which is subjected to hot rolling and is positioned in an austenitic phase area at a cooling speed of 2-5 DEG C / s; stopping accelerated cooling until the temperature of a rail head tread is reduced to be less than 480 DEG C, and air-cooling to room temperature to obtain a steel rail finished product, wherein a microscopic structure of the steel rail finished product is a pearlite consisting of lamellar ferrites and cementite alternately distributed among the lamellar ferrites; the separation distance among pearlite sheets is not more than 120nm; the tensile strength of the steel rail finished product is more than or equal to 1200MPa, and the elongation percentage of the steel rail finished product is more than or equal to 10%. The steel rail disclosed by the invention is capable of resisting marine environment corrosion, has a corrosion rate of less than 1 / 2 of that of carbon and ordinary microalloyed steel rails under equal conditions in a marine environment, and is suitable for application in heavy haul railways with high transportation capacity and high axle load in coastal regions.

Description

Technical field [0001] The invention relates to a steel rail material, in particular to a steel rail resistant to corrosion in the marine environment. Background technique [0002] As a structural member that guides the train and transfers the load to the track bed, the steel rail is directly related to the railway transportation efficiency and driving safety. As railways are exposed to the natural environment for a long time, railway steels must not only meet the requirements of various mechanical properties, but also have certain corrosion resistance. During the service process of steel rails, not only have to withstand various complex stress effects, but also face failure problems caused by long-term corrosion. The railways along the southeast coast of my country are dense, with high traffic density and high total passing weight. Due to long-term service in the marine environment, the rails are severely corroded. On the basis of ensuring the required mechanical properties, th...

AI Technical Summary

Problems solved by technology

First of all, the Cr content is a strengthening element commonly used in rail steel at present. Increasing the Cr content not only significantly improves the strength and toughness, but also improves the corrosion resistance; adding 0.2% to 0.65% of Cu and adding 0.1% to 0.3% of Cu as required Ni can slightly improve the strength and hardness index of the rail without losing ductility and plasticity; for corrosion resistance, if the P content in steel is ≤0.025%, its contribution to the improvement of the corrosion resistance of the rail is limited

At the same time, when the Cu content exceeds 0.5%, it will also cause the deterioration of welding performance, especially the impact toughness of aluminothermic welding, and increase the tendency of copper embrittlement, which is not conducive to the service safety of rails.

In addition, the upper limit of the carbon content in this patent is 0.72%, and the hot-rolled steel rails are used directly on the road. Heavy-haul rail transport demand

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