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Vol.41, No.10, 627 ~ 636, 2003
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| Title |
| Deformation and Oxidation, Quench Embrittlement of Zr-based Alloys in High Temperature Steam Atmosphere |
| 이종혁 Lee Jong Hyeog , 백종혁 Baeg Jong Hyeog , 정용환 Jeong Yong Hwan |
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| Abstract |
| The high temperature deformation and thermal shock tests were performed to estimate the integrity of Zircaloy-4 and advanced cladding under LOCA condition. The high temperature deformation test was carried out at the temperature ranges of 650~950℃ and hoop stress ranges of 20~80 MPa. The thermal shock test was carried out at a individual isothermal oxidation temperature for 500~15000s. A maximum of burst strain occurred at around 800℃, and it decreased to 850~950℃ which is known as temperature range of (α+β) phase in Zircaloy-4. The quenched microstructures generally consisted of three distinct layers such as ZrO₂, α-Zr(O) and prior-β layer. The thickness of ZrO₂and α-Zr(O) layer increased while prior-β layer decreased as the oxidation temperature increased. The hardness measurement was conducted to estimate mechanical properties of the quenched claddings. The hardness decreased in a-layers, then the value decreased slowly or were constant in prior-β. The hardness depends on the oxygen content in the layers. The preliminary results on advanced claddings indicated that LOCA resistance of advanced claddings seem to be superior or comparable to Zircaloy-4 cladding. |
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| Key Words |
| Zircaloy-4, Fuel cladding, Loss of coolant accident, Burst, Thermal shock, Isothermal oxidation, Quench, Zirconium oxides |
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