Rolled steel integral wheel for large-size railway vehicle and production method thereof

Abstract

The present invention provides a steel for large-sized rolling steel integral wheel for railway, the mass percent of its chemical composition is: C 0.46-0.55%, Si0.20-0.37%, Mn0.70-0.85%, Ni0.10-0.25%, Cr0.24~0.32%, Als0.020~0.040%, P≤0.008%, S≤0.008%. The heat treatment process is as follows: heat the wheel after rolling and slow cooling according to the conventional process to 860-880°C with the furnace, keep it warm for 3-3.5 hours, then take it out of the furnace and air-cool it to room temperature, then raise the temperature of the wheel to 840-860°C with the furnace, keep it warm After 3.5-4 hours, immediately cool down to below 550°C after leaving the furnace, then air-cool to room temperature at a cooling rate of 2°C / s-5°C / s, then put the cooled wheel into a furnace at 480-500°C, and keep it warm for 4.5-5 hours. Remove from the oven and air cool.

Description

technical field [0001] The invention belongs to the field of manufacturing rolled steel wheels for railway vehicles, is suitable for large-sized rolled steel integral wheels for railways, and particularly relates to a steel rolled integral wheel with an outer diameter of 1250 mm and a production method thereof. Background technique [0002] Railway wheels have the functions of loading, guiding, transmitting traction and braking force, and the working conditions are very harsh, which has an important impact on traffic safety. With the development of high-speed and heavy-duty railway transportation in my country, the requirements for the quality of railway wheels continue to increase. Therefore, the requirements for the production and preparation methods of wheel steel are getting higher and higher. [0003] The technical conditions of TB / T2708-1996 steel-rolled monolithic wheels for railway express passenger cars and TB / T2817-1997 technical conditions of steel-rolled monolit...

AI Technical Summary

Problems solved by technology

However, for a large wheel with an outer diameter of 1250mm, the metal flow displacement is relatively large during the thermoforming process, the cooling rate of each part is greatly different, and the microstructure of different parts after thermal processing is greatly different, with poor uniformity and severe grains. Inhomogeneity, the conventional heat treatment process can not effectively improve the bad structure inheritance, eliminate the uneven structure produced by rolling, resulting in the mechanical properties of large-size wheels with an outer diameter of 1250mm have not been able to stably meet the requirements of relevant technical conditions, especially the increasingly important toughness requirements

[0006] In the relevant technical conditions of large-size wheels, there are clear requirements for rim strength, hardness, fracture toughness and low-temperature impact resistance. While maintaining high strength and hardness, they must be equally tough. However, for carbon steel, strength, hardness The improvement of toughness will inevitably reduce the toughness. For large-sized locomotive wheels, not only the toughness is low, but also the single value of low-temperature impact toughness and fracture toughness fluctuates greatly, which cannot meet the requirements stably, which seriously affects the qualified rate of large-sized wheels and Use security features

Images