High-strength bainite steel rail and production method thereof

Abstract

The invention relates to a steel rail material and in particular relates to a high-strength bainite steel rail and a production method thereof, which solve the technical problems. The production method comprises the following steps: heating steel containing 0.15wt%-0.30wt% of C, 1.00wt%-1.80wt% of Si, 1.50wt%-2.50wt% of Mn, 0.20wt%-0.60wt% of Cr, 0.05wt%-0.10wt% of Mo and the balance of Fe, rolling the heated steel into a steel rail with needed section, utilizing waste heat of the steel rail, performing accelerated cooling on the rail head of the steel rail at a cooling speed of 3.0-6.0 DEG C / s when naturally cooling the tread surface of the rail head to 450-500 DEG C, stopping accelerated cooling when cooling the center of the tread surface of the rail head to 220-300 DEG C, and performing air-cooling to room temperature to obtain complex phase steel with carbide-free bainite, a small quantity of martensite and a small quantity of residual austenite. The steel is excellent in wear resistance and applicable to heavy haul railway.

Description

technical field [0001] The invention relates to a rail material, in particular to a high-strength bainite rail and a production method thereof. Background technique [0002] The rapid development of railway technology puts forward higher requirements for the service performance of rails. At present, my country's railway rails are mainly pearlite series carbon rails with a carbon content of 0.60% to 0.85%, microalloyed rails and high-strength heat-treated rails, and a small amount of bainite rails are also used. Pearlitic steel rail has the characteristics of simple production process, low production cost, stable structure and performance. However, pearlitic rails also have certain deficiencies, such as low contact fatigue strength at the same strength level, and the rail head is prone to peeling off pieces, cracks, nuclear damage and other damages under the reciprocating stress of the wheels, which is not conducive to the development of railway longevity , especially in re...

AI Technical Summary

Problems solved by technology

However, pearlitic rails also have certain deficiencies, such as low contact fatigue strength at the same strength level, and the rail head is prone to peeling off pieces, cracks, nuclear damage and other damages under the reciprocating stress of the wheels, which is not conducive to the development of railway longevity , especially in recent years, with the continuous increase of railway traffic density and vehicle axle load, the service environment of rails has become more and more harsh, and some road sections, especially curved parts, have been in service for less than a year or even a few months due to serious damage or wear to the limit, etc. The reason is to replace the lower track in advance, which reduces the driving efficiency and brings hidden dangers to the safety of railway transportation

Taking my country as an example, the proportion of 100m long rails has exceeded the previous 25m fixed length. For bainite rails, tempering treatment is required, and the conditions for tempering 100m long rails are not yet available under the current conditions. Limits the large-scale application of bainite rail

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