Name: LEANDRO PRATES FERREIRA DE ALMEIDA
Type: MSc dissertation
Publication date: 24/02/2017
Advisor:
Name |
Role |
|---|---|
| ANTONIO CESAR BOZZI | Co-advisor * |
| CHERLIO SCANDIAN | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ANTONIO CESAR BOZZI | Co advisor * |
| CHERLIO SCANDIAN | Advisor * |
Summary: The study of wheel-rail contact is getting important in Railway Engineering, especially
because rail and wheel represent the second and third largest costs of materials on
the railroad the first is fuel. Usually, the end of life of these components is due to
wear. The contact conditions changes according to the specificities of each railroad,
such as load, speed, track design and materials used, among others. In order to
understand the existing wear mechanisms for the typical contact conditions of the
Estrada de Ferro Vitória a Minas, slip-wear tests were performed in the pin-on-disc
configuration, without lubrication, with variable sliding speed and constant normal load.
The spherical end pins were manufactured from conventional EFVM rail material - 370
Brinell surface hardness pearlitic steel - and the discs were manufactured from AAR
grade Class C cast and forged wheel material. The worn volume of the pins was
calculated based on the diameter of the wear scar. For the discs, the worn volume was
obtained by 3D profilometry. The wear mechanisms were analyzed using a
stereoscopic microscope and a scanning electron microscope. The results indicate an increase in the coefficient of friction in the tests at a speed of 0.9 m/s - μ approximately 0.8 - when compared to the values obtained at a speed of 0.1 m/s - μ between 0.5 and
0.6. The wear severity of both pins and discs was higher in the tests carried out with a
sliding speed of 0.1 m/s. Comparing the different materials of the discs, the wear of
pins and discs was considerably greater in systems with forged wheels. The wear
mechanisms observed were predominantly of plastic nature, with occurrence of
ploughing and adhesion of oxidized materials on the surface of pins and discs.
Key-words: wheel, rail, railroad, slip-wear, pin, disc, wear mechanisms.
