Technical Reports

Linear Friction Welding for Constructing and Repairing Rail for High Speed and Intercity Passenger Service Rail.

  • 05
  • Aug
  • 2016
AUTHOR: Federal Railroad Administration
KEYWORDS: Rail, rail welding, rail joining, linear friction welding, heat affected zone, translational friction welding
ABSTRACT: This project developed a solid-state welding process based on linear friction welding (LFW) technology. While resistance flash welding or thermite techniques are tried and true methods for joining rails and performing partial rail replacement repairs, large heat inputs and residual stresses (associated with rail shortening) can degrade the performance of the welded area. LFW greatly reduces material loss, minimizes shortening of the rail assembly, and reduces weld heat input when compared to traditional rail joining methods. EWI teamed with APCI and LLC to develop a unique 150-ton LFW system, which uses mechanical oscillation and is relatively compact when compared to traditional hydraulic oscillation systems. Weld trails were completed using 136 lb rail. The experiments showed that using LFW to join rail was not only feasible but the technology has the potential to greatly improve the quality of continuously welded rail. Future research efforts should focus on obtaining optimum weld process parameters and reducing weld cycle times by adjusting pre-heat temperatures, oscillation forces, and durations.