Steel rail used for high-speed and quasi-high speed railways and manufacturing method thereof

Abstract

The invention discloses a steel rail used for high-speed and quasi-high speed railways and a manufacturing method thereof. The method comprises: reducing carbon content and utilizing a mode of controlled cooling after rolling to manufacture the steel rail with favorable rolling contact fatigue performance. The steel rail comprises the following chemical compositions by weight percent: 0.40%-0.64% of C, 0.10%-1.00% of Si, 0.305-1.50% of Mn, 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 rare-earth elements, greater than 0% and less than or equal to 0.20% of at least one of V, Cr and Ti and the balance of Fe and inevitable impurities. The steel rail manufactured by the method of the invention maintains the strength and hardness of the existing steel rail of the high-speed railways, and simultaneously has improved plasticity and yield strength; and the energy value needed for initiation and expansion of fatigue microcracks formed on the surface of the steel rail is improved, thus the rolling contact fatigue performance of the steel rail can be improved under the same condition, and finally the service life and transportation safety of the steel rail are improved.

Description

technical field [0001] The invention relates to a rail material, in particular to a rail suitable for use on high-speed or quasi-high-speed railways and a manufacturing method thereof. Background technique [0002] At present, the world's railways mainly include three types: heavy-haul railways, high-speed railways, and passenger-freight mixed railways. For heavy-duty railway rails, due to the heavy train axle (usually 25t-40t), the wheel-rail contact stress is large, and the force is harsh. Usually, the C content is greater than 0.75%, the tensile strength is above 1200MPa, and it has a full pearlite structure. Carbon rail or alloy rail to ensure that the rail has excellent wear resistance. For high-speed railways, because they are mainly used for passenger transport and the axle load of trains is light, it is usually required that the steel rails for high-speed railways have excellent fatigue resistance. For the passenger-freight mixed railway, because it not only undert...

AI Technical Summary

Problems solved by technology

The first method is to use the rail grinding train to regularly grind the upper end of the rail, but the problem with this method is that the cost of grinding the train is expensive, and at the same time, the high-speed and quasi-high-speed railway has a high traffic density and there is no sufficient grinding time

In addition, for the bainite series rails disclosed in the patent CN1074058C, in order to obtain the ideal bainite structure, in addition to requiring a strict control process, a large amount of precious elements must be added, resulting in the manufacturing cost of the rails being much higher than the existing Even if the performance of the pearlite series steel rails is excellent, it is difficult to popularize and use them in large quantities.

[0007] Therefore, for bainitic steel rails, if they are applied to high-speed or quasi-high-speed railways, due to the strict manufacturing process requirements and the need to add a large amount of precious alloys, the manufacturing cost is equivalent to more than twice that of existing pearlitic steel rails. Promoted Use Restricted

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