Fatigue tests of heat-treated rails in the R350HT grade

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.