The passenger car ridge beam durability improving

The article discusses the possibility of extending the service life of passenger cars. The analysis of the state of the passenger car fleet has established that the rate of replenishment of reserved cars has been reduced by more than 40 % over the past 10 years, therefore, it is possible to ensure coverage and replenishment of the retirement of rolling stock of this type after the expiration of the standard service life only by extending the service life of existing cars by carrying out capital repairs with the establishment of a new standard service life. When analyzing the power frame of a reserved seat passenger car, it was found that the greatest static and dynamic loads are perceived by its center beam. It is precisely because of the stresses arising in it that an assessment is formed of the further possibility of operating a car both during its life cycle and further use in diagnostics for the possibility of assigning a new service life to it during overhaul repairs. Studies of a number of elements of center beams cut from passenger cars that have expired the standard period have established that the main characteristics of the metal meet the requirements of safety standards, this indicates that the safety margin and resource inherent in them has not been fully depleted. In the study of the presence of residual stresses that have arisen in the elements cut from the ridge beams, depending on the depth of etching carried out according to the method of N. N. Davidenkov in accordance with the TSNIITmash methodology, the most vulnerable and dangerous places of corrosion that require more careful control during the car maintenance and scheduled preventive repairs were identified. In order to reduce the development of residual stresses and the corrosive effect on the load-bearing frame of a second-class car, recommendations and technological operations have been developed for strengthening the ridge beam by the method of shot-blasting with the formation of a uniform fine-pored structure, which ensures uniform application of paint and varnish coating.