Role of steel composition and welding parameters on the fatigue behavious of high strength welded rail (WELDRAIL)

WELDRAIL is a European Coal & Steel Community promoted project to evaluate the role of steel composition, welding parameters ad post-welding treatments in the improvement of fatigue behaviour of high strength welded rails, with particular regard to both pearlitic (as rolled and head hardened) and bainitic high grade rails. Using these rails the welded joints will be made by both Aluminothermic and Flash Butt welding procedures.

The softening of the Heat Affected Zones (HAZ) of rail welds may deteriorate their fatigue and wear behaviour. This can lead to depressions on the running surface of the rail, disturbing the train passengers' comfort and decreasing the traffic safety due to the additional dynamic impacts and lowered fatigue strength of the welded joints.

The two specific aims of the WELDRAIL project are:

To quantify the role of Heat Affected Zone (HAZ) microstructure, strength and toughness on the bending fatigue behaviour of the high grade rail joints, and to improve the rolling contact fatigue behaviour of welded rails, by the optimisation of both base material chemical composition and welding parameters (and post-welding treatments), thus achieving a good softening resistance of the HAZ.

The project, which commenced on July 1st 2002 and is due for completion on December 31st 2005, consists of a consortium comprising two rail producers and a research institute from across Continental Europe. UK expertise on material characterisation and the in-service monitoring of rails and welds within the UK rail network, being supplied by Corus Research Development & Technology in Rotherham. For more information on the UK expertise available, please contact Mr Lyn Drewett - lyn.drewett@corusgroup.com