Name: ANA CLARA DONNA VOLPONI
Publication date: 30/04/2024
Examining board:
Name |
Role |
|---|---|
| ANTONIO CESAR BOZZI | Examinador Interno |
| CHERLIO SCANDIAN | Presidente |
| HÉLIO GOLDENSTEIN | Examinador Externo |
| NATHAN FANTECELLE STREY | Coorientador |
Summary: The increasing demand for higher load capacity and increased railway traffic highlights the need for enhanced studies on wheel defects, which are crucial for efficiency and safety in railway transportation. To prevent detrimental defects, understanding the damage mechanisms during traffic is essential. By evaluating cast nd forged wheels made of AAR class C and D steels, we identified defects such as shelling, wheel flats, spalling, hollown war, fine flaking, and tread band wear. Hardness measurements along the rim, microhardness in regions close to the surface, and quantitative analyses of inclusions, interlamellar spacing, thicknesses of eformed layers, angles, and sizes of cracks were conducted. Optical and electron microscopy revealed the defect morphologies and their interaction with the microstructure. An extensive database was generated, indicating a low influence of manufacturing processes on the genesis of defects but a strong relationship between microhardness, deformed layer, and surface work hardening. The analysis highlighted the competition between wear and rolling contact fatigue as mechanisms of wheel surface degradation.
