Abstract
The influence of simulated heat-affected zone thermal cycles on the microstructural evolution in a blast-resistant naval steel was investigated by dilatometry, microhardness testing, optical microscopy, electron backscatter diffraction and atom-probe tomography (APT) techniques. Coarsening of Cu precipitates were observed in the subcritical and intercritical heat-affected zones, with partial dissolution in the latter. A small number density of Cu precipitates and high Cu concentration in the matrix of the fine-grained heat-affected zone indicates the onset of Cu precipitate dissolution. Cu clustering in the coarse-grained heat-affected zone indicated the potential initiation of Cu reprecipitation during cooling. Segregation of Cu was also characterized by APT. The hardening and softening observed in the heat-affected zone regions was rationalized using available strengthening models.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5596-5609 |
| Number of pages | 14 |
| Journal | Acta Materialia |
| Volume | 58 |
| Issue number | 17 |
| DOIs | |
| State | Published - Oct 2010 |
Funding
The authors would like to acknowledge financial support from the Office of Naval Research; J. Christodoulou, grant officer. APT measurements were performed at the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph was purchased and upgraded with funding from NSF-MRI (DMR-0420532) and ONR-DURIP (N00014-0400798, N00014-0610539, NOOO14-0910781) grants. Michael D. Mulholland is thanked for his help with APT data evaluation with the IVAS software.
Keywords
- Atom-probe field-ion microscopy (APFIM)
- Electron backscatter diffraction (EBSD)
- Grain boundary segregation
- Precipitation strengthening
- Steels
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys