Welding head rail squaring process

Abstract

An improved method for executing a flash butt weld to join first and second rail segments includes applying a voltage to the first rail segment and the second rail segment to establish a voltage difference between the first and second rail segments. The rail end faces are brought into contact, resulting in an electrical current between the first rail end face and the second rail end face, resistively heating material at the interface. As material burns off at the interface, the power consumed at the rail end interface as a function of rail displacement is periodically sampled. If the comparison indicates that the power per unit of rail displacement is not increasing from sample to sample, the burn-off process is terminated. In a further aspect, if the power per unit of rail displacement exceeds a predetermined threshold, the burn-off process is terminated.

1 .- 9 . (canceled) 
     
     
         10 . An improved in-track weld system for preparing for forge welding of rail segments together in place on a railway, the improved in-track weld system comprising:
 an in-track welding energizing system for supplying a voltage and a current sufficient for welding; and   a controller associated with the energizing system for executing a burn-off procedure prior to executing a welding operation, wherein the controller is adapted to force two rail segments together at an interface while applying a voltage difference across the interface to yield a burn off of material at the interface, and to periodically sample power consumed at the interface as a function of a relative displacement of the rail segments, and terminating the burn-off procedure when the power consumed at the interface is not increasing or exceeds a predetermined threshold.   
     
     
         11 . The improved in-track weld system according to  claim 10 , wherein the voltage and current supplied by the energizing system are AC. 
     
     
         12 . The improved in-track weld system according to  claim 10 , wherein the voltage and current supplied by the energizing system are DC. 
     
     
         13 . The improved in-track weld system according to  claim 12 , wherein the voltage supplied by the energizing system is between about 5 volts and about 12 volts. 
     
     
         14 .- 20 . (canceled)