Laser strengthening technology for surface of steel rail of railway

Abstract

The invention discloses a laser strengthening technology for the surface of a steel rail of a railway. The laser strengthening technology includes the steps that the surface of the steel rail is quenched through lasers, and then a tempering technology is carried out on the steel rail through lasers. Microscopic structures of the steel rail are tempered martensite structures and are optimized with a laser processing technology, evenly-refined sorbite-or-troostite-similar tempered structures with the thickness of 0.8 mm to 1 mm can be obtained on the surface of the steel rail, high rigidity (HRC35-50) and high abrasion resistance are achieved, and meanwhile high bending strength and high fatigue strength are achieved; the sticking resistance, the creeping resistance, the squashing resistance, the side abrasion resistance and the corrugation resistance of the steel rail are improved accordingly. By means of the laser strengthening technology, corrugation, side abrasion and block falling of the steel rail are remarkably reduced on the premise that the mechanical performance such as bending strength, breaking tenacity and fatigue strength of the whole steel rail is guaranteed, the stability and the corrosion resistance of the steel rail are remarkably improved, the service life of the steel rail is remarkably prolonged, the replacement time of the steel rail is prolonged, the maintenance cost of the steel rail is saved, driving resistance is reduced, fuel is saved, and the service period of the steel rail of the railway is prolonged.

Description

technical field [0001] The invention relates to a laser surface strengthening process, in particular to a laser surface strengthening process for railway rails. Background technique [0002] Steel rail is the main component of railway and urban rail transit. Its function is to guide the wheels of traction rolling stock to move forward. The steel rail bears the huge pressure of the wheel, especially on the curve of the track, the pressure of the wheel and rail is higher than that on the straight track. The pressure, friction and impact force are greater, and the adhesion, creep and crushing, side grinding, corrugation, etc. between the wheel and the rail cause the wear and damage of the wheel and rail to be very serious. According to the survey data, 98% of the steel rails on curves in our country are scrapped due to crushing, corrugation, and excessive side wear. With the heavy load and high speed of railway rolling stock, the friction and wear between the wheels and rails ...

AI Technical Summary

Problems solved by technology

[0003] The surface hardness of the steel rail formed by rolling is usually about HRC30 after heat treatment or post-rolling heat treatment such as intermediate frequency quenching, spray quenching and tempering, which leads to a serious lack of wear resistance and serious cracks at the track curve. Wear and tear, especially in the high-speed rail, intercity railway and subway with high passing frequency, which seriously affects the operation efficiency and transportation safety

It is difficult to solve the contradiction of performance requirements such as strength, hardness, impact toughness and contact fatigue strength by using traditional heat treatment methods. If the surface hardness of the rail is significantly increased, the bending strength, impact toughness and fatigue strength of the rail will be significantly reduced