| Title |
Temperature Dependence of Elongation in Zircaloy-4 Nuclear Fuel Claddings |
| Authors |
김순길(Soon Kil Kim),김형섭(Hyoung Seop Kim),홍순익(Sun Ig Hong),최창범(Chang Burm Choi),김규태(Kyu Tae Kim) |
| Abstract |
Temperature and strain rate dependence of elongation and flow stress in Zircaloy-4 CANDU nuclear fuel claddings were studied. The elongation minimum and strain rate sensitivity minimum ocurred at each strain rate and the minima were shifted to higher temperature with increaging strain rate. The loss of ductility associated with dynamic strain aging was observed between 250∼400℃. SEM observation revealed that the fracture surface of Zircaloy-4 nuclear fuel claddings was ductile irrespective of strain rate and temperature. The predicted strain rate sensitivity and elongation are in reasonably good agreement with experimental data in the temperature region of the dynamic strain aging. In the temperature region of the flow stress plateau, the decreases in the strain rate sensitivity due to dynamic strain aging result in a low ductility. Above the temperature range of the flow stress plateau, the high strain rate sensitivity due to dynamic strain aging causes high ductility. |