Innovative Solutions for Manufacturing High-Quality Rails in Ukraine

Abstract

Introduction. The development of railway transport is a necessary factor in the national development and European integration of Ukraine. Problem Statement. Nowadays, over 80% of rail tracks in the national railways does not meet the requirements for bearing high-speed and heavy-load trains and needs to be replaced. At present, Ukrainian Railways corporation buys rails in foreign countries, which requires significant foreign exchange costs, and therefore the manufacture of high-quality mainstream and switch point rails in our country becomes an urgent need. Purpose. To develop innovative options for organizing the production of premium rails in Ukraine. Materials and Methods. Rail steel. Experimental melting and metallographic studies (using the optical and electron microscopy methods). Results. A high homogeneity (high purity of boundaries and dispersion of primary grains, small inter-lamellar distance of perlite), enhanced properties of the rail metal ensured by conventional electroslag remelting (ESR), and similar characteristic of ingot steel produced by ESR in the current-supplying mold with twice as fast speed of formation have been experimentally proved. Experiments with high-speed ESR and test of fluoride slag in the mold on real continuous casting machine has created the technological framework for a hybrid process of continuous casting with electroslag heating of the meniscus in current-supplying mold (CC + ESR). Conclusions. ESR enables reducing the minimum hump rate of casting, improving the density and uniformity of the metal in the axial zone, and maintaining a high quality of the ingot surface. Promising options of technological schemes of waste rail ESR for obtaining the ingots with cross section close to the rail profile have been developed and proposed. Using several modern ESR furnaces with special design will enable satisfying needs of Ukrainian Railways corporation in highquality main and switch point rails. K e y w o r d s : railway, main rail, switch rail, rail steel, CC, ESR, hybrid process, and recycling of used rails. Nowadays, in many countries, the development of transport infrastructure is a priority and a driving force for national economic development. In accordance with the ambitious goals of the Na-tio nal Transport Strategy Drive Ukraine 2030 for the period up to 2030 [1], the development of transport is mentioned among the key factors for Uk raine's national development and European in tegration. The strategy foresees the creation of conditions for the introduction of high-speed