Keywords: self-welding, flowing sodium, 316LN stainless steel, alloy D9, fuel subassembly, fast breeder reactor, cold working, contact stress, shear force, hardness, microstructure, welding
Self-welding susceptibility of 316LN and alloy D9 stainless steels in high-temperature flowing sodium
The self-welding susceptibility of 316LN Stainless Steel (SS) and alloy D9 (15Cr-15Ni-2Mo titanium-modified) SS in 20% cold-worked conditions was evaluated in flowing sodium at 823 K under a maximum contact stress of 12 MPa and for durations of 3, 6 and 9 months. The specimens used were hollow, cylindrical and stacked one above the other under compression using disc springs. The breakaway shear force was measured for self-welded specimens. The results for the two types of SS were compared using scanning electron micrographs, energy dispersive spectroscopic analysis, hardness and microstructures.