| Title |
Research Paper - Transformations - : Effects of Oxygen and Heat - Treatment on the Microstructure of Nuclear Fuel Cladding Material |
| Authors |
송승현(Seung Hyun Song); 홍현선(Hyun Seon Hong); 이경섭(Kyung Sub Lee) |
| Abstract |
The effects of oxygen content on the microstructure and the phase transformation temperature of modified Zr alloys for nuclear fuel cladding were studied. The changes in microstructure with varying cooling rates were also investigated. The cooling rates of 0.7 and 30℃/s resulted in Widmansta¨tten structure and the cooling rate of 1000℃/s resulted in martensitic structure. As oxygen content increased, Widmansta¨tten structure was changed from basketweave to parallel plate structure and the plate width was increased. The presence of large amount of oxygen causes parallel plate structure by raising phase transformation temperature and widening (α+β) two phase region. However, martensitic structure was not affected by oxygen contents and showed fine acicular α structure in all specimens. Hardness increased with increasing oxygen content due to solid solution hardening and also increased with increasing cooling rate due to α plate refinement in Widmansta¨tten structure and due to the formation of ω phase in martensitic structure. |