Prospects for scientific support to ensure the reliability of the Djalinda – Nizhny Bestyakh – Magadan railway line, based on the study of structural degradation of materials and assessment of the wheel–rail lifetime in low temperature environment

Abstract

This study is based on the results of investigations into the structural degradation of railway wheel and rail materials after service, as well as on studies of seasonal wear and damage of the «wheel–rail» system under the conditions of Central Yakutia. It is demonstrated that long-term cyclic loading is accompanied by changes in the structural state of the metal, decreases of fracture resistance and nonlinear processes of damage accumulation. It has been established that the estimating service life based solely on accumulated tonnage fails to account for changes in material properties during operation. The study highlights the need to simultaneously consider the structural state of material, the temperature conditions, the wheel-rail contact interaction, the track geometry, and the characteristics of the permafrost foundation. A concept of monitoring is proposed that integrates the optical metallography, scanning electron microscopy, and mechanical testing with the monitoring of wear levels and operational characteristics. The principal directions for experimental verification of the residual life model for the projected railway line has been formulated. In this context, it is necessary to transfer the methodology for investigating material degradation – validated on an operational section of a railway line in Central Yakutia conditions – to the task of providing a preliminary scientific basis for the reliability of future railway infrastructure, while mandatorily verifying the practical applicability of the established patterns through experimentation.