新锆合金氧化膜的晶体结构分析

Crystal Structure Analysis of Oxide Film of New Zirconium Alloy

采用静态高压釜实验研究了NZ2合金在360℃,18.6MPa含Li水和400℃,10.3MPa蒸汽中的腐蚀动力学,通过X射线衍射法研究了NZ2合金在两种介质中腐蚀不同时间后氧化膜的晶体结构。结果表明:NZ2合金在360℃含Li水中腐蚀速率较400℃蒸汽中的低;随着腐蚀时间的延长,氧化膜中四方氧化锆含量逐渐降低,单斜氧化锆含量逐渐增高,四方氧化锆向单斜氧化锆转变。腐蚀转折时,氧化膜中出现了立方氧化锆,随后氧化膜中立方相含量明显增多,说明四方相向单斜相转变过程中,立方相是作为过渡相存在。氧化膜中四方相含量越高,腐蚀速率越低。

The corrosion kinetics of NZ2 alloy were investigated by static autoclave test in 360℃ lithiated water and 400℃ steam. The crystal structure of oxide film of NZ2 alloy, corroded in two above mentioned kinds of mediums, was studied by XRD method in this paper The results of corrosion kinetics indicated that the corrosion resistance of NZ2 alloy in 360℃/18.6 MPa lithiated water was better than that in 400℃/10.3 MPa steam. The content of t-ZrO2 in oxide film decreased, the content of m-ZrO2 increased with the prolongation of corrosion time, t-ZrO2 transited to m-ZrO2. And c-ZrO2 appeared in oxide film when corrosion transition happened, then the content of c-ZrO2 increased obviously. That means c-ZrO2 was transition phase during transformation of t-ZrO2 to m-ZrO2. Corrosion resistance was improved when the content of t-ZrO2 in oxide film increased.