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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 Raman spectroscopy was used to investigate the crystal structure of NZ8 alloy after being corroded in a static autoclave at 360 ℃ for lithium water and 400 ℃ steam. The results show that the oxide film of NZ8 alloy is mainly composed of monoclinic zirconia, including a small amount of distorted tetragonal zirconia. With the extension of the etching time, the content of average tetragonal zirconia in the oxide film decreased continuously, the content of monoclinic zirconia increased continuously, and the tetragonal zirconia transformed to monoclinic zirconia. From the oxide film / substrate interface to the outer surface of the oxide film, the content of tetragonal zirconia continuously decreases, and the content of tetragonal zirconia at the interface is the highest. The content of tetragonal zirconia at the oxide film / metal interface of NZ8 alloy after being corroded at 360 ℃ for 98 days is higher than that of the tetragonal zirconia oxide at 400 ℃ for 70d. The content of tetragonal zirconia at the oxide film / The outer surface of the oxide film is not formed with tetragonal zirconia. The transformation of tetragonal zirconia to monoclinic zirconia determines the corrosion resistance of NZ8 alloy. The higher the content of tetragonal zirconia in the oxide film, the better the corrosion resistance of the zirconium alloy.