摘要
通过拉曼光谱法研究秦山核电厂一期反应堆内运行后的燃料棒Zr-4合金包壳外表面不同部位氧化膜的晶体结构。结果表明,在燃料棒底端,腐蚀程度相对较低,含有较高含量的四方相,表面也呈致密黑色,随着距底端的距离增加,腐蚀程度增加,外表面由黑白相间过渡到疏松白色,氧化膜中四方相氧化锆含量逐渐减少,逐渐转变为单斜相;在径向上,从氧化膜/金属界面到表面,四方相含量逐渐减少,单斜相氧化锆含量升高。与堆外试验结果类似,即四方相向单斜相氧化锆的转变决定锆合金包壳材料在堆内的抗腐蚀性能,单斜相含量越高,腐蚀速率越高,耐腐蚀性能越差。
The crystal structure of the oxide film of Zr-4 alloy of different positions from the bottom of fuel rod, which comes from Qinshan nuclear power plant phase 1, is investigated by Raman spectroscopy method. The results indicate that the bottom of the rod has better corrosion resistance and more tetragonal ZrO_2, and has the black appearance which is compact. With the increasing of the distance from the bottom, the corrosion is more and more severe, the average content of tetragonal ZrO_2 in the oxide film decreases, that of monoclinic ZrO_2 increases, and tetragonal ZrO_2 transforms into monoclinic ZrO_2, and there is a gradual transition from the black and white appearance into white and porous appearance. In the cross section, from the oxide/metal interface to the surface of the oxide film, the content of tetragonal ZrO_2 reduces gradually and the monoclinic ZrO_2 increases. The result is similar to the investigations in the autoclave, i.e., the transformation from tetragonal ZrO_2 to monoclinic ZrO_2 decides the corrosion resistance of Zr-4 alloy in the reactor, and the higher the m-ZrO_2 content in the oxide film is, the higher corrosion rate of cladding, and the worse corrosion resistance property.
出处
《核动力工程》
EI
CAS
CSCD
北大核心
2017年第S1期110-114,共5页
Nuclear Power Engineering
