UO2烧结块高温蠕变性能的试验研究

The experimental research on high temperature creep properties of UO_2 pellets

对晶粒度分别为9.0μm、23.8μm的UO2烧结块进行了高温蠕变试验。结果表明:在相同温度、相同载荷下,UO2烧结块晶粒尺寸越小,稳态蠕变速率越大;在相同温度下,稳态蠕变速率的对数值与应力的对数值之间存在线性关系,且随着载荷增大,UO2烧结块的稳态蠕变速率增大;在相同载荷下,随着温度升高,UO2烧结块的稳态蠕变速率增大。对于晶粒度分别为9.0μm、23.8μm的UO2烧结块,在载荷为10 MPa下的高温蠕变速率没有数量级的差别。

The high-temperature creep properties of sintered UO2 with two grain size （9.0 μm and 23.8μm） were studied in this paper. The results show that the creep rate becomes a little faster with the reduction of the UO2 grain size at the same temperature and the same load. At the same temperature, the relation between logarithm of the steady creep rate and logarithm of stress is linear , and with load increasing, the steady creep rate of the sintered UO2 pellets increases. At the same load, the steady creep rate of the sintered UO2 increases with the temperature increasing, the creep rate of sintered UO2 at the load of 10 MPa are almost the same for the grain size of 9.0μm and 23.8μm.