NZ8合金在360℃锂水和400℃蒸汽中腐蚀后氧化膜的拉曼光谱分析(英文)

Raman Spectroscopy Analysis of Oxide Film of NZ8 Alloy Corroded in 360°C Li Water and 400°C Steam

通过拉曼光谱法研究NZ8合金在360℃锂水和400℃蒸汽的静态高压釜中腐蚀后氧化膜的晶体结构。结果表明,NZ8合金的氧化膜主要由单斜氧化锆组成,其中包括少量畸变的四方氧化锆。随着腐蚀时间的延长,氧化膜中平均四方氧化锆含量不断减少,单斜氧化锆含量不断增加,四方氧化锆在向单斜氧化锆转变。从氧化膜/基体界面到氧化膜外表面,四方氧化锆含量不断减少,界面处四方氧化锆含量最高。NZ8合金在360℃锂水中腐蚀98d后所得氧化膜/金属界面处四方氧化锆含量较其在400℃蒸汽中腐蚀70d所得氧化膜/金属界面处四方氧化锆含量高,而且在400℃蒸汽中腐蚀后氧化膜外表面没有四方氧化锆形成。四方氧化锆向单斜氧化锆的转变决定了NZ8合金的耐腐蚀性能。氧化膜中四方氧化锆含量越高,则锆合金的耐腐蚀性能越好。

The crystal structure of the oxide film of NZ8 alloy,corroded by static autoclave test in 360 °C Li water and 400 °C steam was investigated by Raman spectroscopy method in this paper,The results indicate that the oxide film of NZ8 alloy is mainly composed of monoclinic ZrO2,including a small amount of distorted tetragonal ZrO2.With the prolongation of corrosion time,the average content of the distorted tetragonal ZrO2 in the oxide film decreases,that of monoclinic ZrO2 increases,and tetragonal ZrO2 transforms into monoclinic ZrO2.From the oxide/metal interface to the surface of the oxide film,the content of tetragonal ZrO2 reduces gradually and it is the highest at the interface.At the same time,the tetragonal ZrO2 content at the interface of NZ8 alloy oxide film,gained in 360 °C Li water for 98 d,is much higher than that in 400 °C steam for 70 d,and tetragonal ZrO2 is not observed at the surface of the oxide film exposed to 400 °C steam.The transformation from tetragonal ZrO2 to monoclinic ZrO2 decides the corrosion properties of NZ8 alloy.Corrosion resistance is improved when the content of tetragonal ZrO2 in oxide film increases.