| Abstract Scope |
Stainless Steel (SS) 316H is a promising candidate for structural components in nuclear systems for its elevated operating temperature range, its corrosion resistance, its fabricability, and its attractive mechanical properties. There is now significant interest in additively manufactured (AM) 316 stainless steel (SS), which would provide fabrication of complex components with minimal waste. Compared to the AM 316L (low-carbon version), there is an insufficient amount of characterization and analysis of AM 316H, especially for radiation studies. Literature has extensively shown that process parameters can affect the microstructure and radiation response, but has not compared the effect of printing methods and parameters on radiation response. In this study, AM 316H is printed from Laser Powder Bed Fusion (LPBF) and Laser Direct Energy Deposition (LDED), then ion irradiated with 5 MeV Fe+2 ions at 400, 500, and 600°C. Transmission Electron Microscopy (TEM) is used to study the cellular structure evolution for the different printing methods, and Scanning Transmission Microscopy (STEM) will be used for STEM/EDS to determine the chemical segregation at cellular boundaries as a function of temperature. The formation of cell structures is due to the thermal gradient and solidification rate. The results show that the LPBF’s cellular structure is finer (due to high solidification rate) with higher dislocation density compared to the coarser dendrites (lower solidification rate) and lower dislocation density for LDED. LPBF showed more segregation of Fe, Si, and Mo at the boundaries compared to LDED. The temperature effect on the cellular structure evolution will be further discussed. |