Abstract
Cellular structure with high-density dislocations and elemental segregation is a unique characteristic for laser powder bed-fusion (L-PBF) 316 L stainless steels (SSs), but the role of such structure to stress corrosion cracking (SCC) remains pending. Herein we adopt multiple verification methods, including transmission electron microscope, atomic force microscopy and density-functional theory calculations to unveil its advantageous contribution to SCC resistance in high-temperature oxygenated water. Convincing evidence verify that the intrinsic Cr/Mo segregation across cellular boundaries (CBs) initiates a diffusion-induced stress and a nano-scale galvanic cell to provide a robust and stable Cr/Mo source towards near-surface grain boundaries (GBs). Consequently, there exists a Cr/Mo-rich enrichment zone at the crack tip, improving the re-passivation capacity of the SCC tip.
| Original language | English |
|---|---|
| Article number | 112636 |
| Journal | Corrosion Science |
| Volume | 244 |
| DOIs | |
| Publication status | Published - 1 Mar 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
The financial support from National Natural Science Foundation of China (12275176), China National Nuclear Cooperation Jingying Project, and Lingchuang Research Projects, Scientific Research Program for Young Talents of China National Nuclear Corporation and Finnish SAFER2028 (National Nuclear Safety and Waste Management Research Programme 2023-2028) LOAD project (Long-term Operation on Aging and environmental Degradation of nuclear reactor materials) are acknowledged..
Keywords
- Stainless steel
- Stress corrosion cracking
- Laser powder-bed-fusion
- Cellular structure
