Study of Dynamics of Corrosive Wear of Load-Bearing Metal Structures of Subway Cars with Expired Service Life

The present study focuses on scientific and experimental research on corrosion damage to the bodies of subway cars. The main purpose of the research is to assess the degree of corrosive wear on the main load-bearing metal structures of the subway cars after the end of their service life in order to determine the possibility of their further operation. Scientific and experimental research was conducted under the conditions of the municipal enterprise “Kyiv Metro” on subway cars of the series (models) Yezh, 81-714/717 and 81-714.5/717.5, which had reached the end of their service life. The main methodological approach of the research consisted of conducting technical diagnostics of the subway cars using standardized non-destructive testing methods. The goal of the research was achieved by solving two main tasks. The first task was to determine mathematical expressions describing the dynamics of changes in the thickness and degree of corrosive wear of the metal structures of the studied subway cars, depending on number of years in operation. The second task was to determine the possibility of extending the service of the subway cars after reaching the end of their service life. The scientific novelty of this study lies in determining the degree of thinning and the development of corrosive wear of the metal structures of the studied subway cars depending on the type of structure and service life. The practical significance of the obtained results lies in the possibility to predict the residual strength resources of the individual elements of the metal structures of the studied cars using the corrosive wear criterion. It was established that the 092GS material of the main metal structures of the subway car bodies is sufficiently resistant to corrosion processes. The results of the research show that the metal structures of the subway cars studied had a margin of safety and, therefore, their service life could be extended.