TRANSMISSION ELECTRON MICROSCOPY STUDY OF HELIUM BEARING FUSION WELDS [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2008.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Additional Creators:
- United States. Department of Energy. Savannah River Site
United States. Department of Energy
United States. Department of Energy. Office of Scientific and Technical Information
- A transmission electron microscopy (TEM) study was conducted to characterize the helium bubble distributions in tritium-charged-and-aged 304L and 21Cr-6Ni-9Mn stainless steel fusion welds containing approximately 150 appm helium-3. TEM foils were prepared from C-shaped fracture toughness test specimens containing δ ferrite levels ranging from 4 to 33 volume percent. The weld microstructures in the low ferrite welds consisted mostly of austenite and discontinuous, skeletal δ ferrite. In welds with higher levels of δ ferrite, the ferrite was more continuous and, in some areas of the 33 volume percent sample, was the matrix/majority phase. The helium bubble microstructures observed were similar in all samples. Bubbles were found in the austenite but not in the δ ferrite. In the austenite, bubbles had nucleated homogeneously in the grain interiors and heterogeneously on dislocations. Bubbles were not found on any austenite/austenite grain boundaries or at the austenite/δ ferrite interphase interfaces. Bubbles were not observed in the δ ferrite because of the combined effects of the low solubility and rapid diffusion of tritium through the δ ferrite which limited the amount of helium present to form visible bubbles.
- Published through SciTech Connect.
International Hydrogen Conference 2008.
Tosten, M; Michael Morgan, M.
- Funding Information:
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