The paper presents a summary of research on the possibility of influencing the state of residual stresses in railway rails by changing the pass design of vertical and horizontal straightener rollers and optimising their distribution on the rail perimeter. The presented results are devoted to the influence of profiled rollers on the level of residual stresses. A wide range of theoretical considerations were carried out based on the use of the finite element method using the commercial Forge software package. In order to verify the results of the theoretical considerations most reliably, a series of “in situ” experiments were conducted in industrial conditions on an existing production line. The tests were carried out on 120 meters long 60E1 railway rails. A significant reduction in the level of residual stresses compared to the standard requirements was achieved.

This article presents the results of comparative tests for rails produced at the end of the nineteenth century using the steel production processes used at that time in relation to currently produced rails in the standard, not heat-treated R260 steel grade, and heat-treated high-hardness R350HT steel grade. Detailed results of steel quality assessment are presented, including oxide cleanness tests and macro- and microstructure analyses for each rail. The influence of the main elements on the morphology of the microstructure of individual rails is discussed, illustrating the description with numerous photos. An analysis of the chemical composition of each steel grade is provided, analysing the differences in the chemical composition of rails from different manufacturing processes. The results of hardness measurements in the rail head as an indicator of the rails’ abrasion resistance are also presented. The article also discusses the steel production processes used since the mid- nineteenth century, taking into account their positive and negative features in relation to the currently used steel production process.

The study highlights the advancement of rail transport, focusing on the distinct requirements of high-speed passenger transit and robust freight operations. Passenger rails emphasize geometric precision, such as straightness and minimal dimensional deviation, to reduce vibrations and improve...

The article presents the results of industrial experiments carried out on a demonstration line for heat treatment of railheads installed in the heavy section mill of AMP Branch in Dąbrowa Górnicza. An analysis of the chemical composition of the tested rails and the level of basic mechanical properties were presented, as well as a detailed discussion of the fatigue testing procedure was carried out in accordance with the scope of qualifying tests provided for rails in the EN13674-1 standard. The results of determination of the stress intensity factor, fatigue crack growth rate and fatigue strength for rails in the R350HT steel grade are presented. The requirements for modern heat-treated rails are also discussed and the key parameters of rail properties that determine their operational properties are indicated.

The article presents the results of the last stage of work on the impact of changes in the roll pass design on the state of residual stresses in railway rails. The discussed stage includes the summary of industrial experiments of rolling 60E1 rails with a length of 120 meters using a modified pass design of roll grooves. The rolling technology has been deeply modified, ranging from the finishing stand, through the pre-finishing stand, to the semi-finishing stand. The rails in this experiment were cooled using standard cooling technology and then straightened using innovative vertical straightener shaped rollers. Residual stresses were tested using the strain gauge method and the hole-drilling strain gauge method by drilling a hole in the rail axis and at a distance of 14 millimetres from its axis. The resulting tensile stresses in the rail foot were reduced to an average level of less than 43% in relation to the requirements of the EN13674-1 standard.

The required rail straightness is achieved by straightening with roller straighteners. The consequence of the straightening operation is the introduction of residual stresses to the straightened rail. An excessive level of residual stresses accumulated in the rail during use in the track may lead to its damage or fracture. ArcelorMittal Poland S.A., in cooperation with Łukasiewicz Research Network – Institute for Ferrous Metallurgy, carried out a research project (POI R.01.02.00-00-0167/16) the aim of which was to reduce residual stresses in railway rails by changing the technological parameters of the straightening process. The results of the presented study relate to rails 60E1 and 60E2. The study includes the measurement, testing, calculations and analyses of the obtained results. The conducted research indicates the possibility of obtaining a low level of residual stress in the rails for a system consisting of a 7-roller vertical straightener and a 9-roller horizontal straightener by changing the roller settings, the shape of the rollers, the shape of the rail foot and its curvature.