氧化介质对锆合金高频氧化膜的形成及性能影响  

Oxidation Mediumon Formation and Properties of High Frequency Oxide Film of Zirconium Alloy

作　　者：罗傲然 连利仙[1] 刘颖[1] Luo Aoran;Lian Lixian;Liu Ying(School of Materials Science and Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学材料科学与工程学院,四川成都610065

出　　处：《稀有金属》2024年第7期913-921,共9页Chinese Journal of Rare Metals

基　　金：四川省重大科技专项课题(2019ZDZX0022);中广核军工技术开发项目(HG2018117)资助。

摘　　要：在空气、纯氧和原子化氧气3种介质下,利用高频氧化技术对锆合金管进行了氧化处理,对比研究3种介质对氧化膜形成过程、微观结构和性能的影响。采用X射线衍射(XRD)、背散射电子(BSE)分析和透射电镜(TEM)对氧化膜的显微结构进行表征,重点分析原子化氧气条件下氧化膜的形成机制,并通过原位微/纳米力学测试系统和高温高压水腐蚀试验分别对氧化膜的硬度、耐磨性和抗腐蚀性能进行评价。结果表明:在3种氧化介质下形成的氧化膜连续均匀,主要由大量的单斜相氧化锆(m-ZrO_(2))和少部分四方相氧化锆(t-ZrO_(2))组成。其中在原子化氧气条件下获得的氧化膜层最厚,TEM显示外层氧化膜主要为单斜等轴晶粒,随着氧化的进行,压应力逐渐增大,在氧化膜中部区域出现了单斜柱状晶,而在氧化膜/金属界面由于压应力最大从而稳定了四方等轴晶粒。同时,在3种介质下形成的氧化膜纳米硬度和耐磨性与原样相比都有很好的改善,其中原子化氧气条件下形成的氧化膜纳米硬度比原样提高约700%,磨损体积降低约60%。抗腐蚀能力也有明显提高,原子化氧气下的腐蚀增重最低,比原样降低约90%。Zirconium alloys are considered as cladding materials for current and future nuclear reactors because of their excellent corrosion resistance,high temperature mechanical properties,neutron stability and good chemical compatibility with nuclear fuel.However,when zirconium alloy is used as cladding material,the inner wall cladding is usually eroded by fission products,and the outer wall is subjected to high temperature and high pressure water corrosion,fretting wear and foreign body erosion,which requires the formation of a wear-resistant and anti-corrosion protective layer on the surface.Therefore,in this paper,zirconium alloy tubes were oxidized under the oxidizing conditions of 615℃for 40 min in air,pure oxygen and atomized oxygen.The effects of three oxidizing media on the formation process,microstructure and properties of the oxide film were compared and studied.The microstructure of the oxide film was characterized by X-ray diffraction analysis(XRD),back scattering electron analysis(BSE)and transmission electron microscope analysis(TEM).The formation mechanism of the oxide film under atomized oxygen condition was analyzed.The hardness,wear resistance and corrosion resistance of the oxide film were evaluated by in-situ micro/nano mechanical test system and high temperature and high pressure water corrosion test,respectively.The results showed that:In the air,the pure oxygen and oxygen atomization under three kinds of medium,zirconium alloy tube surface could form a continuous uniform layer of oxide film,which under the condition of atomic oxygen could obtain the most thick layer of oxide film,and this was because the atomic oxygen containing oxygen possesses higher oxidation activity,zirconium and oxidizing reaction matrix faster,and oxygen concentration of oxygen atomization was the highest,Therefore,a thicker oxide film could be formed in the same time.The XRD results showed that the oxide films formed under the three oxidation atmospheres are all composed of a large amount of monoclinic zirconia m-ZrO_(2)

关 键 词：锆合金 高频氧化 氧化膜 组织结构 性能 

分 类 号：TG172.82[金属学及工艺—金属表面处理] TG146.414[金属学及工艺—金属学]