Bainite steel wheel for high-tenacity rail transit and manufacture method thereof

Abstract

The invention provides a bainite steel wheel for high-tenacity rail transit and a manufacture method thereof. The bainite steel wheel comprises 0.10-0.40% of C, 1.00-2.00% of Si, 1.00-2.50% of Mn, 0.20-1.00% of Ni, 0.001-0.040% of RE, smaller than or equal to 0.020% of P, smaller than or equal to 0.020% of S and the balance of Fe and unavoidable residual elements, wherein Si plus Ni is larger than or equal to 1.50% and smaller than or equal to 2.50%, and Si plus Mn is larger than or equal to 2.00% and smaller than or equal to 4.00%. Compared with the prior art, the bainite steel wheel has the advantages that through a heat treatment technology, a rim of the wheel has a non-carbide bainite structure; spokes and a hub have metallographic structures taking granular bainites and supersaturated ferrites as main components; the wheel has high comprehensive mechanical properties, such as yield strength, tenacity and low-temperature tenacity; and besides, the cost is reduced, the service life of the wheel is prolonged, and comprehensive benefits are increased.

Description

technical field [0001] The invention belongs to the fields of steel chemical composition design and wheel manufacturing, and in particular relates to a high-toughness rail transit bainite steel wheel and a manufacturing method thereof, as well as a steel type design and manufacturing method for other parts and similar parts of rail transit . Background technique [0002] "High speed, heavy load and low noise" is the main development direction of rail transit in the world. Wheels are the "shoes" of rail transit and one of the most important walking parts, which directly affects the safety of operation. During the normal operation of the train, the wheel bears the full load of the vehicle and is damaged by wear and rolling contact fatigue (RCF). The action relationship is in a dynamic and alternately changing stress state. In particular, wheels and rails, wheels and brake shoes (except for disc brakes) are two pairs of friction pairs that exist all the time and cannot be ign...

AI Technical Summary

Problems solved by technology

[0010] (1) The yield strength of the rim is low, generally not exceeding 600MPa. Because the rolling contact stress between the wheel and the rail is large during the operation of the wheel, sometimes exceeding the yield strength of the wheel steel, the wheel is plastically deformed during operation, resulting in the subsurface of the tread Plastic deformation occurs, and because there are brittle phases such as inclusions and cementite in the steel, it is easy to cause micro-cracks on the rim, and these micro-cracks will produce defects such as peeling and rim cracking under the action of rolling contact fatigue of the wheel.

[0011] (2) The carbon content in the steel is high, and the thermal damage resistance is poor. When the tread brake is used or the wheel is scratched when the wheel slides, the local temperature of the wheel is instantly raised to the austenitization temperature of the steel, and then quenched, resulting in martensite Body, so repeated thermal fatigue, forming brake thermal cracks, resulting in defects such as peeling and falling blocks

[0012] (3) The hardenability of the wheel steel is poor, and the wheel rim has a certain hardness gradient, and the hardness is uneven, which is prone to defects such as wheel rim wear and out-of-roundness

Although this type of steel has good strength and toughness, the cross section of the rail is relatively simple, and the impact toughness at 20°C is not high, and the cost of the steel type is high

Images