Work

The purpose of the work is to develop recommendations on the chemical composition and modes of heat treatment of steel with the formation of various structural states to increase the cross-sectional hardness of the head of a high-strength rail. To achieve this goal in the course of work it is necessary to solve the following tasks: -perform the analysis of chemical compounds used in the manufacture of railway rails; to conduct an analytical review in order to determine the prospects for the application of new trends, taking into account economic feasibility; to evaluate the influence of alloying elements on the kinetics of phase transformations. -manufacture ingots of steels of experimental composition, to investigate the contamination of non-metallic inclusions of experimental rail ingots, to investigate the primary cast structure of experimental steels, - to analyze reference data on the kinetics of austenite decay of steels of different chemical composition; using mathematical modeling to determine the limits of the allowable range of cooling rates of the surface and central parts of the rail head of different chemical composition with accelerated cooling: maximum allowable cooling rates of the skating surface to prevent the formation of martensite structures and the minimum required cooling rates documentation, including the formation of a homogeneous bainite structure. -develop recommendations for heat treatment modes that ensure the formation of the structure of bainite in the rail head of steels of different chemical composition. The value of the work is to increase the service life of railway transport of Ukraine by increasing the wear resistance of the railway, which will increase its durability, ie to reduce the cost of freight. Thus, the work aimed at improving the mechanical properties of railway products by developing chemical compositions and technological parameters of heat treatment is relevant.