Characterisation of High-Carbon Steel Surface Welded Layer

Abstract

In this paper microstructural and mechanical properties of high-carbon steel surface welded layer obtained with self-shielded flux cored wire are presented in standard rails and crossings. The testing results of tensile characteristics, hardness, toughness via instrumented Charpy pendulum, microstructural analysis and fatigue crack growth resistance of all characteristical zones are analyzed in detail, especially from the point of view of interaction between microstructure and properties. The obtained results indicate superior properties of repaired welded layers, which is due to their similarity to the new generation of bainitic steel, i.e., due to the change of microstructure from original pearlitic structure to final bainitic structure. Finally, fatigue crack growth parameters have shown that deposite layer has higher resistance than the crack growth, improving overall reliability of rails and crossings.