Abstract
An overview of critical variables that affect fatigue failure with respect to steel components in ultralong life regimes is presented. The key role of hydrogen trapped by non-metallic inclusions in the ultralong life fatigue failure process is documented. The role of non-metallic inclusions on ultralong fatigue life is shown in the master curve of ODA (Optically Dark Area surrounding a non-metallic inclusion at fracture origin) growth. The master curve of ODA growth shows the correlation of the size of the ODA with the size of the non-metallic inclusion as it corresponds to fatigue life. The ability to predict the presence of non-metallic inclusions in steels with extreme value methods is incorporated with the master curve of ODA growth to determine the maximum threshold stress for ultralong fatigue life using the √area parameter model. Most machine components experience variable loads in service. A design approach is introduced for calculating the effects of different loading levels for ultralong fatigue life.
| Original language | English |
|---|---|
| Pages (from-to) | 140-149 |
| Journal | International Journal of Fatigue |
| Volume | 41 |
| DOIs | |
| Publication status | Published - 2012 |
| MoE publication type | A1 Journal article-refereed |
| Event | International Symposium on Fatigue Design & Material Defects - Trondheim, Norway Duration: 23 May 2011 → 25 May 2011 |
Keywords
- Fatigue design
- high strength steel
- non-metallic inclusion
- the area parameter model
- ultralong fatigue life