Authors: I.I. Chumachkov, S.V. Konovalov

Title of the article: Influence of rail end geometry on the quality characteristics of welded joints without heat treatment

Year: 2026, Issue: 1, Pages: 26-41

Branch of knowledge: 2.5.8. Welding, related processes and technologies

Index UDK: 625.143.482

DOI: 10.26730/1999-4125-2026-1-26-41

Abstract: The most vulnerable areas for the formation and development of defects in welded rails are their joints. In the welding zone, a temperature gradient causes regions of reduced hardness to appear. Cracks and spallings develop in these areas, which can subsequently lead to the integrity loss of the welded string. Modifying the end-face geometry of the rails prior to welding allows for the formation of a weld of controlled shape, redistribution of stresses in the joint, and an increase in its strength. Changing the inclination angle of the end faces along the rolling axis helps to reduce the dynamic impact during rail service. The purpose of this work is to continue the research on the influence of the end-face geometry of R65-type rails of DT350 grade on the mechanical properties and residual stresses of welded joints without heat treatment. Six experimental configurations obtained by flash-butt welding with pulsation on an MSR-63.01A machine using 650 mm long samples with different end-face shapes were considered. It was shown that altering the inclination angle of the rail ends leads to stress redistribution in the joint zone and changes the residual stress profile. Welding rails with end faces inclined at 20° provides optimal mechanical properties: the fracture load reached 2173 kN at a deflection arrow of 27.8 mm. Changing the inclination angle from horizontal to vertical increases strength and ductility (up to 2235 kN and 32.7 mm, respectively), but leads to joint geometry distortion and makes subsequent hot straightening impossible.

Key words: flash-butt welding railway rails welded butt joint profile three-point bending microstructure mechanical properties residual stresses

Receiving date: 27.10.2025

Approval date: 15.01.2026

Publication date: 19.03.2026

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