Steel rail and its surface treatment method

Abstract

The invention discloses a steel rail. After the steel rail surface is subjected to reinforcement treatment, the steel rail has gradient hardness in the length direction and is distributed with a plurality of hardness periods in the length direction, wherein each hardness period comprises a first hardness zone, a second hardness zone and a third hardness zone which are sequentially distributed; the third hardness zone of each hardness period is connected with the first hardness zone of the adjacent hardness period; the length of the first hardness zone is a first preset length, and the Brinell Hardness is A-B; the length of the second hardness zone is a second preset length, and the Brinell Hardness is C-D; the length of the third hardness zone is a third preset length, and the Brinell Hardness is E-F; and A is greater than C, E is greater than C, C is greater than 470HB, and D and F are respectively less than 550HB. The invention also discloses a surface treatment method of the steel rail. The method can greatly improve the wear resistance and service life of the steel rail, reduce the phenomena of cracking, shedding and breaking on the steel rail surface and enhance the safety of the steel rail.

Description

technical field [0001] The invention relates to the field of railway transportation equipment and production, in particular to a steel rail with stepped hardness and a surface treatment method thereof. Background technique [0002] In recent years, my country's railways are in a stage of rapid development, and more and more modern railways are being built. With the increase of train speed and load capacity, many new problems have been exposed during the use of steel rails. [0003] In passenger and freight mixed railways, U75V rails or heat-treated rails with higher hardness are usually used in my country. The surface Brinell hardness (HBW10 / 3000) of U75V rails is 280-320HB, and the surface Brinell hardness (HBW10 / 3000) of heat-treated rails is 320-320HB. 420HB. After the rail is laid and operated for a period of time on the small curve radius line (curve radius ≤ 800m) of the passenger-freight mixed railway, intermittent alternating contact fatigue cracks will appear on th...

AI Technical Summary

Problems solved by technology

After the rail is laid and operated for a period of time on the small curve radius line (curve radius ≤ 800m) of the passenger-freight mixed railway, intermittent alternating contact fatigue cracks will appear on the rail, which is manifested by the appearance of rail treads or rail angles at approximately 45° to the wheel rolling direction. For oblique cracks at an angle of °, the crack length is generally 10-25mm, and the depth is 2-5mm. In severe cases, it can reach more than 10mm. Affect the service life of rails and driving safety

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