Study of the thermo-mechanical damage in steels for shoe-braked railway wheels using innovative small-scale tests / Studio del danneggiamento termomeccanico di acciai per ruote ferroviarie frenate a ceppi mediante test innovativi small-scale

The behavior of three railway wheel steels (HYPERLOS®, ER-TEN, and SUPERLOS®) coupled with two brake block materials (cast iron and organic composite) and R260 rail steel was studied by means of an innovative small-scale test bench, hereafter called 4-contact machine. This bench simulated the thermal and mechanical damage experienced by real railway wheels during braking. Com- parative tests were conducted to assess rolling contact fa- tigue and wear damage for each material combination. The results aligned with actual operational damage, revealing differences in material performance. Cast iron block samples exhibited higher wear and generated a carryover material layer on the wheel samples, while the composite brake block samples wore less. Although the tested wheel steels showed similar behaviour, the extent of observed dam- age varied, with some materials experiencing more damage than others.