Abstract
R350HT is a standard premium heat-treated rail steel and the reference for new rail steel development. The present study discusses an experimental characterization of fatigue crack growth rate and fracture toughness for this refined pearlitic rail steel in mode-I-loading. The tests are carried out on compact tension specimens extracted from the rail head with the straight notch pointing to the rail foot. As a result, the crack path orientation approximates deep rolling contact fatigue cracks. The fracture surfaces obtained under cyclic and monotonic loading are compared by means of scanning electron microscopy. The results are analyzed and discussed with reference to the morphology of the fracture surfaces for the crack initiation sites, fatigue crack growth region, and the final fracture region, evidencing the role of the microstructure, and inclusions on the fracture behavior. From the analysis of the crack path and fracture surface, it is concluded that the refined microstructure and ferrite ductility play an important role in fracture behavior.
| Original language | English |
|---|---|
| Pages (from-to) | 219-226 |
| Journal | Procedia Structural Integrity |
| Volume | 47 |
| DOIs | |
| Publication status | Published - 2023 |
| Event | 27th International Conference on Fracture and Structural Integrity, IGF 2023 - Hybrid, Rome, Italy Duration: 1 Feb 2023 → … |
Keywords
- fatigue crack growth rate
- fracture toughness
- R350HT