Residual stress changes in railway rails

Abstract

Railway rail manufacturing involves repeated hot-rolling followed by cooling during which differential contraction and phase changes occur in the rail. Subsequent roller straightening, heat treatments and the passage of trains combine to generate a complex residual stress pattern. Results are presented of internal residual stress distributions measured in a new and a used rail using the neutron strain scanning technique. The results are compared with conventional destructive strain gauge measurements and with theoretical predictions and are discussed in terms of their effects on possible rail failure fatigue mechanisms.