Application of Translational Friction Welding for Rail Assembly and Repair

摘要

Joining new rails end-to-end or inserting repair sections is most often performed using thermite welding or flash butt welding. This study examined the use of an alternative technology, translational friction welding(TFW)for attaching rail. This process offers potential for minimal shortening of the rail during welding, with equipment comparable to the flash butt welding used today. Translational friction welds are formed by oscillating one part relative to the other while a force is applied. This oscillation under load creates in interfacial heating, enabling upsetting the workpieces creating a solid-state joint. For the work done here, initial weld parameters were derived from published work. Specific practices were explored in an iterative fashion. Full area rail sections were welded, achieving near parent metal strength with low hardness levels for the rail head and the rail web. The specific equipment employed necessitated the use of low friction forces. These low friction forces resulted in non-uniform heating of the rail interfaces, with variations in properties. While TFW of rail sections has been demonstrated, next generation systems will be required to demonstrate the performance necessary for implementation.