Effect of Stress Mitigation on Precipitation Kinetics of Alloy 22 Welds
Understanding the phase stability of Alloy 22 (N06022) is important since the precipitation of tetrahedrally close-packed (TCP) phases over time has been known to adversely affect corrosion and mechanical properties. Prior observations have shown that these phases precipitate during the welding process. After welding, residual stresses due to the solidification and cooling from temperature remain. When the weld cannot be stress-relieved by solution annealing, the application of commercially available stress-mitigation processes such as low plasticity burnishing (LPB) and laser shock peening (LSP) may be used to produce near-surface compressive stresses. This study involved examination of cross-sectional samples of aged 1.25 inch thick welds of Alloy 22 plates using electron backscatter diffraction (EBSD) for TCP identification and micrograph analysis for TCP quantification. Precipitation in both the as-welded and LSP weld was observed primarily in inter-dendritic regions whilst precipitation in the LPB weld was in both inter- and intra-dendritic regions.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15014663
- Report Number(s):
- UCRL-CONF-209248; TRN: US0800928
- Resource Relation:
- Conference: Presented at: 2005 TMS Annual Meeting and Exhibition, San Francisco, CA (US), 02/13/2005--02/17/2005; Other Information: PBD: 26 Jan 2005
- Country of Publication:
- United States
- Language:
- English
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