International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The effect of inclusions and corrosion products on the mechanism of wear of railway wheels made of R7 steel and also of rails made of R7 steel M76. was studied. The research was carried out by several methods: metallographic, electron microscopy, X-ray, micro-X-ray spectral analysis. The features of the formation of wear particles near nonmetallic inclusions and corrosion products related to structural changes near the treads of railway wheels and rails as well as to the interaction of steel with the surrounding atmosphere during operation were investigated. The influence of various factors on the role of nonmetallic inclusions and corrosion products in the formation of wear particles is shown, which makes it possible to predict the nature of wear of the rolling surface of railway wheels and rails under various operating conditions. The main sources and the mutual influence of various factors on the formation of wear particles near nonmetallic inclusions and corrosion products have been established, which makes it possible to predict the nature of wear of the rolling surface of railway wheels and rails under various operating conditions.

During operation, under the influence of mechanical stress, temperature, and external environment, the initial structure of a railway wheel undergoes changes that lead to its fatigue-corrosion wear.
The wheels with different tread profiles that were removed from operation due to the maximum wear of the rims were studied. The studies were carried out using the metallographic method (Neophot-21) and scanning electron microscope JSM-35.
The causes of cracks and wear particles formation near the tread surface of railway wheels associated with phase and structural changes occurring during operation were analyzed. The possibilities of changing the tread profile due to uneven wear were established. It was shown that structural and phase changes near the tread surface are associated with the development of plastic shifts due to the action of external loads, thermal stresses during braking, and the formation of “white layers” when the metal is heated by the heat of braking and abrupt cooling when the brakes are turned off. The role of non-metallic inclusions and corrosion products of wheel steel in the formation of cracks near tread of railway wheels has been established.

The features of structural changes in the cove zone on the tread of worn out railway wheels were investigated. The influence of laser processing in pulsed and continuous mode on the nature of the structure and properties of wheel steel was shown. The influence of laser treatment on the increase in the hardness and wear resistance of wheel steel has been established. It was shown possibility and necessity of local laser hardening of cove zone of railway wheels tread by coming out of bainite structure. A method for improving the wear resistance of the tread by local laser treatment has been proposed.