Abstract
Crack initiation in AISI 316 stainless steel has been investigated. Persistent slip bands (PSBs) were characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). PSBs on the surface of the material increase the surface roughness and result in crack initiation. EBSD data from near the crack initiation region were used to correlate the global and local misorientations of the grains, plastic deformation, and Schmid factor with the fatigue life of specimens. The crack initiation region was found to have the highest misorientations. The region near crack initiation was found to have more plastic deformation, which was severe in specimens loaded with higher stresses. The kernel average misorientation (KAM) and grain reference orientation deviation (GROD) maps from the EBSD data were investigated for specimens that failed at different fatigue cycles. It was found that the interaction of high dislocation density, substructuring, and misorientation of low-angle grain boundaries in the region of plastic deformation resulted in fatigue crack initiation.
| Original language | English |
|---|---|
| Pages (from-to) | 1893-1904 |
| Number of pages | 12 |
| Journal | Fatigue and Fracture of Engineering Materials and Structures |
| Volume | 48 |
| Issue number | 4 |
| Early online date | 3 Feb 2025 |
| DOIs | |
| Publication status | Published - Apr 2025 |
Funding
This work was supported by the Lloyd's Register Foundation's ICON Studentship Award (ICON\u20102019\u201003). The Lloyds Register Foundation is a charitable foundation helping to protect life and property by supporting engineering\u2010related education, public engagement and the application of research.
| Funders | Funder number |
|---|---|
| Lloyd’s Register Foundation | ICON‐2019‐03 |
| Lloyd’s Register Foundation |
Keywords
- Schmid factor
- electron backscatter diffraction
- fatigue crack initiation
- kernel average misorientation
- persistent slip bands (PSBs)
ASJC Scopus subject areas
- General Materials Science
- Mechanics of Materials
- Mechanical Engineering