Influence of welding on microstructure and strength of rail steel

Abstract

In this study, metallurgical and mechanical aspects of cold flash butt welded rail joints were investigated. The relationship between the material characteristics and the distance to the fusion line were evaluated. Significant changes observed in grain size as it ranges 2-8 according to ASTM E 112. Hardness tests conducted and the average results of the rail head, web, and foot were recorded. According to the results, three different zones were identified including the fusion line, recrystallization zone, and transition areas. Tensile properties and strength characteristics have been investigated for the specified zones separately. Obtained experimental values were used as input parameters for the developed finite element model (FEM) to calculate stress distribution. The welded rail was subjected to realistic wheel load and stress distributions in weld were evaluated. The developed model has also been validated by comparing the theoretically obtained stress values with the experimental ones under various loading conditions. (C) 2020 Elsevier Ltd. All rights reserved.