Zr-2.5Nb合金在500℃,25MPa超临界水中的腐蚀行为  

Corrosion Behavior of Zr-2.5Nb Alloy in Supercritical Water at 500 ℃ by 25 MPa

作　　者：鲍一晨[1] 张乐福[1] 朱发文[1] 

机构地区：[1]上海交通大学核科学与工程学院,上海200240

出　　处：《腐蚀科学与防护技术》2013年第5期398-401,共4页Corrosion Science and Protection Technology

基　　金：国家重点基础研究发展计划项目(2007CB209802)资助

摘　　要：采用动态高压釜实验研究了Zr-2.5Nb合金在500℃,25 MPa的超临界水中的腐蚀行为。通过SEM,EDS,XRD等对腐蚀实验后的试样进行了分析。结果表明,在超临界水中Zr-2.5Nb合金的腐蚀速率较快,初期表面生成黑色光亮的氧化膜,主要由四方相ZrO2构成,随着腐蚀时间增长,表面逐渐转变为灰白色的单斜相ZrO2且产生了大量裂纹;原本表面已覆盖ZrO2涂层的试样腐蚀后发生涂层剥落的现象,且腐蚀速率无明显减缓。四方相ZrO2的存在对Zr-2.5Nb合金的抗氧化性能有积极的作用,随着腐蚀时间延长,逐渐出现的单斜相会破坏表面氧化膜的保护性,从而恶化材料的耐蚀性能。The corrosion behavior of Zr-2.5Nb alloy specimens with and without ZrO2 coating was investigated in supercritical water （SCW） at 500 ℃ by 25 MPa. SEM, EDS and XRD were used to characterize the morphology, element distribution and crystal structure of the oxide scales. The Zr- 2.5Nb alloy exhibited large mass gain after exposure to SCW. The surface oxide on specimens without coating is mostly tetragonal phase at the beginning of exposure, and then gradually transformed to monoclinic phase with the increasing time. Cracks can be observed on the oxide scales on noncoated specimens, while exfoliation can be found on ZrO2 coated specimens. It is considered that the tetragonal phase in oxide scale is beneficial, while the monoclinic phase is detrimental to the corrosion resistance of zirconium alloy.

关 键 词：ZR-2 5Nb合金 超临界水 四方相 单斜相 氧化膜 

分 类 号：TG172.9[金属学及工艺—金属表面处理]