Corrosion-resistant microalloyed steel and steel rail and preparation method of corrosion-resistant microalloyed steel and steel rail

Abstract

The invention relates to a steel rail material, in particular relates to a corrosion-resistant microalloyed steel, and aims to solve the technical problem that the corrosion-resistant microalloyed steel is not provided. The corrosion-resistant microalloyed steel is prepared from the following components by weight percent: 0.73% to 0.85% of C, 0.30% to 0.90% of Si, 0.80% to 1.20% of Mn, 0.20% to 0.40% of Cr, 0.30% to 0.50% of Cu, Ni accounting for one half to two thirds of the content of the Cu, 0.03% to 0.05% of P, less than or equal to 0.025% of S, at least one element from 0.04% to 0.12% of V, 0.02% to 0.06% of Nb or 0.005% to 0.05% of Re, and the balance of Fe and inevitable impurities. The microscopic structure of a steel rail product is formed by pearlite and a trace quantity of ferrites, wherein the tensile strength of the steel rail product is greater than or equal to 1000MPa, so that the steel rail product is good in marine environment corrosion resistance and atmospheric environment corrosion resistance. Thus, the steel rail product is suitable for coastal regions and tunnels with a high relative humidity.

Description

technical field [0001] The invention relates to a rail material, in particular to a corrosion-resistant micro-alloyed rail and a preparation method thereof. Background technique [0002] As a structural member that guides the train to run and transmits the load to the ballast bed, the rail is directly related to the transportation efficiency and driving safety of the railway. Because railways are exposed to the natural environment for a long time, the steel used for railways must not only meet the requirements of various mechanical properties, but also have certain corrosion resistance. During the service process of rails, they not only have to bear various complex stresses, but also face failure problems caused by long-term corrosion. In semi-humid or arid climates, rails made of ordinary carbon or micro-alloyed steels usually do not affect their service life due to corrosion problems during their service life. In contrast, the steel rails laid in the coastal or bridge-tu...

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 improves the strength and toughness significantly, 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%, it is still helpful for the corrosion resistance of the marine environment, but in the acidic environment of the atmosphere, its resistance Corrosion performance cannot be effectively improved

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.

At the same time, the upper limit of carbon content in this patent is 0.72%, and the strength level of steel rails is low, which can only meet the needs of high-speed and ordinary passenger-cargo mixed railways, and it is difficult to meet the needs of large-axle load, large-capacity and heavy-haul railway transportation

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