Abstract
The influence of the hardness of martensite and ferrite phases in dual phase steel on void formation has been investigated by in situ tensile loading in a scanning electron microscope. Microstructural observations have shown that most voids form in martensite by evolving four steps: plastic deformation of martensite, crack initiation at the martensite/ferrite interface, crack propagation leading to fracture of martensite particles and void formation by separation of particle fragments. It has been identified that the hardness effect is associated with the following aspects: strain partitioning between martensite and ferrite, strain localisation and critical strain required for void formation. Reducing the hardness difference between martensite and ferrite phases by tempering has been shown to be an effective approach to retard the void formation in martensite and thereby is expected to improve the formability. © 2012 Institute of Materials, Minerals and Mining.
| Original language | English |
|---|---|
| Journal | Materials Science and Technology (United Kingdom) |
| Volume | 28 |
| Issue number | 9-10 |
| Pages (from-to) | 1092-1100 |
| ISSN | 0267-0836 |
| DOIs | |
| Publication status | Published - 2012 |
Keywords
- Ferrite
- Hardness
- Martensite
- Morphology
- Scanning electron microscopy
- Tempering
- Martensitic steel