Abstract
This article presents the results of tests on heat-treated R350HT grade rails, which were manufactured on a railhead heat treatment line installed in the heavy section mill of the AMP Branch in Dabrowa Gornicza. The research article presents an analysis of the chemical composition of the tested rails and their basic mechanical properties. It also discusses in detail the fatigue testing procedure performed in accordance with the qualification tests specified for rails in the EN13674-1 standard and the DBS 918 254-1 technical specifications. Microstructure analysis, including pearlite morphology assessment, and macrostructure evaluation results are presented. Results of determining the stress intensity factor, fatigue crack growth rate, fatigue strength, and determination of vertical and horizontal fatigue strength using the staircase method for R350HT steel grade rails are also presented. The requirements for modern heat-treated rails are also discussed, and key rail property parameters that determine their operational properties are identified.