High Temperature Creep Properties of UO2 Fuel Pellets Manufactured by Low Temperature Sintering Technology

2013 ◽  
Author(s):  
Rui Li ◽  
Yuemin Zhou
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Low Temperature ◽  
Uranium Dioxide ◽  
Nitrogen Atmosphere ◽  
Creep Process ◽  
Low Temperature Sintering ◽  
High Temperature Creep ◽  
Creep Properties ◽  
Temperature Creep

In this paper, the low temperature sintering technology to UO2 pellets has been introduced, and we have studied the high temperature creep properties of the pellets which manufactured by low temperature sintering. The sintering temperatures are 1073K, 1273K, 1473K and 1673K, sintering time are 1 hour, 2 hours and 3 hours respectively. We obtained the highest sintering density of pellets at 1673K with 3 hours, which is 10.41g/cm3 (94.98% theoretical density). The grain size of pellets which prepared by low temperature sintering technology and traditional technology are 9.0μm and 23.8μm respectively. So the high temperature creep properties of the two kinds of pellet must be studied. They were performed at 20–50 MPa, 1673K and 1773K respectively, under a nitrogen atmosphere to shorten the experimental time. According to the results, the creep rates of sintered UO2 with the grain sizes of 9.0μm and 23.8μm under the load of 10MPa are almost the same. The creep process is controlled by both Nabarro-Herring creep and Hamper-Dorn creep for uranium dioxide with grain size of 9.0μm; while Hamper-Dorn creep is the dominant mechanism for uranium dioxide with grain size of 23.8μm.

scholarly journals Effect of Grain Size on the High Temperature Creep Properties of 17Cr-14Ni Steel

1979 ◽  
Vol 65 (7) ◽  
pp. 896-905 ◽  
Author(s):  
Yoshihiro KONDO ◽  
Takashi MATSUO ◽  
Takayuki SHINODA ◽  
Ryohei TANAKA
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
High Temperature Creep ◽  
Creep Properties ◽  
Temperature Creep

scholarly journals Effect of Heat Treatment on Microstructure and Creep Behavior of Fe-40Ni-24Cr Alloy

2021 ◽  
Vol 11 (17) ◽  
pp. 7951
Author(s):  
Maureen Mudang ◽  
Esah Hamzah ◽  
Hamid Reza Bakhsheshi-Rad ◽  
Filippo Berto
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Creep Behavior ◽  
Gas Turbines ◽  
High Temperature Creep ◽  
Creep Properties ◽  
Temperature Creep ◽  
Heat Treated ◽  
Sliding Mechanism ◽  
Iron Nickel

Iron-nickel-chromium (Fe-Ni-Cr) alloy Haynes HR120 is an iron-nickel-based superalloy, which is extensively used in gas turbines. Hence, the materials for the fabrication of steam turbine blades should present great mechanical characteristics and creep properties. In this study, Fe-40Ni-24Cr was heat-treated at temperatures from 950 to 1250 °C. High temperature creep behavior and microstructure evolution of the selected heat-treated (1050 °C, 1200 °C, 1225 °C and 1250 °C) Fe-40Ni-24Cr alloy were assessed at temperatures of 800 °C and 900 °C under 100 MPa stress. The alloy consisted of titanium and niobium rich precipitates, namely NbC, (Nb,Ti)C, TiN and Ti(C,N) distributed in the matrix grain boundaries, which enhance the creep properties of the alloy. The hardness of heat-treated Fe-40Ni-24Cr alloy decreased with increasing temperature and grain size. The creep strain of the Fe-40Ni-24Cr alloy increased with escalation in the creep time and the temperature being under constant applied stress. Fe-40Ni-24Cr alloy shows a decrease in steady-state creep rate with an increase in grain size from 62 μm to 183 μm due to the grain boundary sliding mechanism and 183 μm to 312 μm due to the occurrence of dislocation climb. This result exhibited that grain size has a significant influence on the alloys’ high temperature creep properties.

Research on High Temperature Creep Properties of Al2O3-SiO2 Ore (Al2O3 ~ 65)

2016 ◽  
Vol 680 ◽  
pp. 343-346 ◽  
Author(s):  
Yong Qiang Sun ◽  
Yong Li ◽  
Shuo Cao ◽  
Hao Bo Zhang ◽  
Chang He Gao ◽  
...  
Keyword(s):  
High Temperature ◽  
Creep Resistance ◽  
Softening Temperature ◽  
Creep Process ◽  
High Temperature Creep ◽  
Creep Properties ◽  
Temperature Creep ◽  
Bauxite Ore ◽  
Two Stages ◽  
Good Creep Resistance

High temperature creep properties of Al2O3-SiO2 ore (65% Al2O3 by mass percentage, abbreviation for Al2O3~65) was studied. The results show that the creep rates at 1300 °C × 50h, 1400 °C × 50h and 1500 °C × 50h were-0.89% ,- 1.75%, - 5.76%,respectively. At 1300 °C, ore has good creep resistance. As the temperature increases, the high temperature creep resistance of Al2O3 ~ 65 bauxite ore is significantly reduced. Creep process can be divided into two stages: when the time t <30h, the sample are in the densification process; after 30 hours, the creep properties show that the relationship between time and the creep rate is linear. At 1300 °C, the absolute value which is the slope of the linear relationship is smaller, exhibited an excellent high-temperature creep resistance. The loading softening-temperature of Al2O3 ~ 65 bauxite ore is 1343 °C. The Sample phase and microstructure are characterized by X-ray diffraction and scanning electron microscopy (SEM). The results show that mullite reticular is formed in sample at 1300 °C; at this point, TiO2 mostly exist as Rutile. At 1400 °C and 1500 °C, TiO2 mostly exist as Aluminum titanate, Corundum phase portion into mullite.

scholarly journals Effect of Grain Size on High Temperature Creep Properties of Hastelloy X

1981 ◽  
Vol 67 (10) ◽  
pp. 1805-1814 ◽  
Author(s):  
Yoshihiro KONDO ◽  
Takashi MATSUO ◽  
Takayuki SHINODA ◽  
Ryohei TANAKA
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
High Temperature Creep ◽  
Hastelloy X ◽  
Creep Properties ◽  
Temperature Creep

High-temperature creep properties of uranium dioxide pellet

2010 ◽  
Vol 20 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Jia-cheng GAO ◽  
Liang-fen WANG ◽  
Yong WANG ◽  
Shu-fang WU
Keyword(s):  
High Temperature ◽  
Uranium Dioxide ◽  
High Temperature Creep ◽  
Creep Properties ◽  
Temperature Creep
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