A kind of bainitic steel wheel for rail transit produced by low-cost fine-tuning and its manufacturing method

Abstract

The invention discloses a bainitic steel wheel for rail transit produced at low cost and fine-tuned, and a manufacturing method thereof. , rare earth RE: 0.001~0.040%, phosphorus P≤0.020%, sulfur S≤0.020%, the rest is iron and unavoidable residual elements; and 3.00%≤Si+Mn≤5.00%. Compared with the existing technology, through the alloy design and manufacturing process, especially the heat treatment process and technology, the wheel rim obtains a carbide-free bainite structure; the spoke plate and the hub obtain a granular bainite and supersaturated ferrite structure And a small amount of pearlite, the wheel has high comprehensive mechanical properties; no special alloying elements such as Mo, Ni, V, Cr and B are added, and the heat treatment process and technology are fully utilized to greatly reduce the cost of steel and realize precise production.

Description

technical field [0001] The invention belongs to the field of steel manufacturing, and specifically relates to a bainitic steel wheel for rail transit produced by low-cost fine-section production and a manufacturing method thereof, realizing bainitic steel wheel for rail transit through low-cost fine-section production, and other similar Component steel design and manufacturing methods. 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 pa...

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

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