Wheel steel and heat treatment method and application thereof

Abstract

The invention relates to wheel steel and a heat treatment method and application thereof. The wheel steel comprises, by weight, 0.57-0.67% of C, not larger than 1.00% of Si, not larger than 1.20% of Mn, not larger than 0.025% of P, not larger than 0.025% of S, and the balance Fe and unavoidable impurity elements. The wheel steel is used for manufacturing wagon wheels. The heat treatment method comprises the following steps that firstly, the temperature of the wheels is increased to 850 DEG C to 870 DEG C along with the temperature of a furnace; secondly, heat preservation is conducted; thirdly, spray cooling is conducted on rims; fourthly, when the temperature of the middle portions of wheel disks is reduced to 730 DEG C to 740 DEG C, air cooling is conducted on the wheel disks; fifthly, air cooling is conducted; sixthly, heating, tempering and heat preserving are conducted. On the basis that the strength of the wagon wheels subjected to heat treatment and containing 0.57-0.67% of carbon goes near to that of a common medium and high carbon steel wheels, the impact property of the wheel disks is remarkably improved, and therefore the good comprehensive mechanical property is obtained, and the use safety performance of the wheels is improved.

Description

technical field [0001] The invention relates to the field of manufacturing rolling steel wheels for railway vehicles, in particular to a heat treatment method for steel rolling integral wheels for railway freight vehicles with an axle load of 25t to 30t and a running speed of ≤120km / h. Background technique [0002] my country's current railway freight vehicle wheel standard is the railway industry standard TB / T2817-1997 "Technical Conditions for Rolled Steel Integral Wheels for Railway Vehicles" promulgated in 1997, which is mainly applicable to railway freight vehicle wheels with a running speed of not less than 120km / h . The C content requirement of conventional CL60 steel in this standard is 0.55-0.65%, which has not changed for decades. In recent years, traditional wheel steels have been exposed to a large number of problems under heavy load and speed-up conditions, including severe wear and edge rolling, increased wheel peeling and block loss, and sharply shortened whee...

AI Technical Summary

Problems solved by technology

[0004] For CL65 steel wheels whose C content is in the range of medium and high carbon steel, the new railway industry standard requires that the microstructure of the wheel rim should be fine pearlite and a small amount of ferrite after quenching and tempering treatment. The notable feature is that the increase in hardness will lead to a decrease in impact toughness, thereby reducing the internal crack growth resistance of the wheel. When the wheel is subjected to complex wheel-rail interaction forces during service, it will have a negative impact on the safety performance of the wheel. Negative Effects

[0005] In the process of research and development of medium and high carbon steel CL65 wheels by Maanshan Iron and Steel Co., Ltd., the CL65 wheels trial-produced according to the conventional rolling and heat treatment process of the wheels have the phenomenon that the average value of the impact toughness of the web plate is low and the margin is insufficient, which cannot meet the predetermined strength. Based on the better impact toughness of the radial plate, the safety performance of medium and high carbon steel wheels is reduced

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