On the optimal ratio of the hardness of wheel and rail steel, ensuring minimal wear of the wheel-rail friction pair

Abstract

In this work, to identify the optimum between the hardness of the wheel and the rail, which ensures minimal wear, methods were used to determine wear by mass loss (volumetric wear) and by micrometric measurement of the size of the imprint (linear wear). It has been shown that the optimal range of wheel and rail hardness, determined by measuring (reducing) the size of the indentation, is in the range of 1.38-1.55. This interval practically confirms the wear identified by mass loss of 1.41-1.58. Based on these data, it is recommended to use the average value of the ratio between them, namely, 1.39-1.56 (HVк556-655, HVр400-420), which does not violate the objectivity and accuracy of measurements, both when determining volumetric and linear wear. It is noted that there is no magic relationship between the hardness of a wheel and a rail; there is only an optimal hardness for wheels and rails, determined by several internal (chemical composition, structure, properties, etc.) and external (friction coefficient, degree of slippage, presence or absence of lubrication, axle loads, etc.) factors.