Flash-butt welding is used in the manufacture of continuously-welded rails. Finished welds typically exhibit high levels of tensile residual stresses in the rail web and at the upper surface of the rail foot, which may increase the risk of fatigue failure under in-service loading conditions. Reducing the magnitude of the residual stresses, for example by modification of the welding conditions or application of post-weld heat-treatment, may alleviate this risk. An understanding of the influence of the welding process, including the post-weld cooling conditions, short term post wold heat treatment and accelerated cooling, on the residual stress distribution is necessary in order to improve the performance of flash-butt welds through the application of post-weld heat treatment. In addition, incorrect post-weld treatment conditions that may have adverse effects on both the residual stress distribution and material characteristics in the welds would need to be avoided.
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