Bainitic steel wheel for rail traffic with capability of resisting against damp, hot and corrosive environments and manufacturing method thereof

Abstract

The invention discloses a bainitic steel wheel for rail traffic with capability of resisting against damp, hot and corrosive environments and a manufacturing method thereof. The bainitic steel wheel comprises the following chemical components: 0.05-0.40% of C, 0.40-1.50% of Ni, 0.25-1.50% of Cr, 0.70-2.10% of Mn, 0.20-1.00% of Si, 0.01-1.00% of W, 0.05-0.60% of Mo, 0.01-0.80% of Cu, 0.01-0.20% ofV, 0.001-0.20% of Nb, 0.0001-0.0350% of B, 0.001-0.040% of RE, less than or equal to 0.020% of P, less than or equal to 0.020% of S and the balance of Fe and inevitable residual elements, wherein Mn+Cr is more than or equal to 2.0% but less than or equal to 3.0%. The new alloy design system of C-Ni-Mn-Cr-Mo-Cu and alloying principle are adopted by the invention; after a wheel is formed, a rim after advanced thermal treatment is endowed with a carbide-free bainite structure; the wheel has excellent comprehensive mechanical property and service performance, especially, atmospheric corrosion resistance; the wheel is capable of resisting against damp, hot and corrosive environments and reducing the harmful influences of stress corrosion and medium corrosion; the service life and running safetyof the wheel can be further promoted.

Description

technical field [0001] The invention belongs to the technical field of rail transit, and relates to a bainitic steel wheel for rail transit that is resistant to damp heat and corrosive environment and a manufacturing method thereof. Background technique [0002] At present, the wheel steels used for rail transit at home and abroad, such as Chinese wheel standards GB / T8601, TB / T2817, European wheel standards EN13262, Japanese wheel standards JRS and JIS B5402, and North American wheel standards AAR M107, etc., are all medium and high carbon carbon steels. The metallographic structure of steel or medium and high carbon microalloyed steel is ferrite-pearlite structure. In general, no alloying elements are added to the wheel steel. On the one hand, due to the high C content, the strength and hardness of the wheel can meet the technical requirements, and no alloy is added from the perspective of economy; on the other hand, if the alloy is added, the CCT curve will change signific...

AI Technical Summary

Problems solved by technology

[0006] (1) The yield strength of the rim is low, generally not exceeding 650MPa. 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.

[0007] (2) The carbon content in the steel is high and the thermal damage resistance is poor

[0008] (3) The wheel steel is carbon steel with poor hardenability

There is a certain hardness gradient in the rim of the wheel, and the hardness is uneven, which is prone to defects such as rim wear and out-of-roundness

[0009] (4) It does not contain corrosion-resistant alloy elements, the oxide scale on the surface of the wheel has poor ability to resist damp heat and corrosive environments, and the chemical electrode potential difference between ferrite and cementite is large, which is easy to generate corrosion micro-batteries, resulting in the overall corrosion resistance of the wheel Difference

[0010] (5) Under low temperature conditions, the toughness of the wheel drops significantly. Once a crack source is generated, it will expand rapidly and eventually form a crack and break

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