研究了Hastelloy C-276(C-276)镍基合金在650℃/25 MPa超临界水中的腐蚀特性.采用扫描电镜、X射线能谱仪、X射线衍射和X射线光电子能谱分析了氧化膜的腐蚀形貌、组织结构和合金元素分布.研究结果表明,C-276合金在650℃/25MPa的超临界水中的腐蚀过程主要是Ni的溶解,由于不能形成均匀、完整的氧化膜,合金在超临界水中并不具备优越的耐腐蚀性能,其双层结构的氧化膜富Cr而贫Ni、Mo,外层疏松的大颗粒(Ni(OH)2和NiO)为金属溶解和氧化物沉淀形成,内层(Cr2O3)的生长则是水穿过氧化物微孔作用的结果.%The corrosion behavior of nickel-base alloy Hastelloy C-276 was investigated in supercritical water (SCW) at 650 ℃/25 Mpa. SEM, EDS, GIXRD and XPS were used to analyze the corrosion morphology, structure and element distribution of oxide film. The results show that the corrosion process of C-276 alloy at 650 ℃/25 Mpa in SCW is mainly dissolution of Ni. Since it can not form a uniform and complete oxide film, the alloy in SCW is not well placed to corrosion resistance. The dual-layer oxide film structure which is formed on C-276 is rich in Cr but poor in Ni, Mo. The outer layer consisting of loose and large grains Ni(OH)2 and NiO agrees with dissolution and precipitation mechanism, while the growth of the Cr2O3 inner layer is the result of water through the porous oxides.
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