Full-scale testing of laser clad railway track; case study - testing for wear, bend fatigue and insulated block joint lipping integrity

摘要

This paper reports on a series of tests which were carried out on full-scale sections of rail that\udhad been treated by laser cladding aiming to create a layer (~1-2mm) of high performance\udmaterial on the rail head. Experiments were designed to measure wear, lipping of insulated\udblock joints (IBJs) and bending fatigue of clad samples. The wear rate of the clad samples was\udbetween 78- 89% lower than that of the standard R260 reference sample. Cladding of either\udside of an insulated block joint greatly improves its lipping resistance and allows it to withstand\udapproximately 3 times the energy input into the contact compared to a standard un-clad IBJ. A\udsection of rail clad with martensitic stainless steel was subject to bend fatigue testing and ran\udout to 5,000,000 cycles at a stress range of 350 MPa matching the performance of an unclad\udR260 rail. Although there is no standard for the bend testing of laser clad rail this performance\udexceeds the performance requirements of the NR/SP/TRK111 standard which governs the bend\udtesting of flash but welded rail.