高温高压水中镍基合金表面氧化膜的原位表面增强型拉曼光谱

In-situ Surface Enhanced Raman Spectroscopy of Surface Film Formed on Nickel-based Alloys in High-temperature and High-pressure Water

摘要: 采用表面增强型拉曼光谱方法原位研究了镍基合金在高温高压水环境中的腐蚀行为及其表面生成氧化膜.Ni-5Cr-8Fe表面氧化膜的拉曼光谱存在三个拉曼峰,位于540 cm-1,610 cm-1和670 cm-1.610 cm-1峰的出现表明了氧化膜中存在Cr2O3.540 cm-1峰则说明氧化膜中含有Cr2O3或NiO或两者的混合物.670 cm-1峰对应于FeCr2O4尖晶石的生成.Ni-10Cr-8Fe的表面氧化膜由Cr2O3、FeCr2O4构成,可能含有一定的NiO.Ni-10Cr和Ni-20Cr的表面氧化膜主要为Cr2O3,没有发现尖晶石相的存在.随着合金中铬含量的增加,表面氧化膜中Cr2O3的含量增加,NiO成分减少.

Abstract: In-situ surface enhanced raman spectroscopy (SERS) was used to investigate the surface films formed on Ni-based alloys.SERS spectra measured for oxides of Ni-5Cr-8Fe shows Raman peaks at 540 cm-1,610 cm-1,and 670 cm-1.The peak at 610 cm-1 indicates the presence of Cr2O3.540 cm-1 peak is attributed to Cr2O3 or NiO or the mixture of both.670 cm-1 peak is assigned to FeCr2O4 spinel.The surface film of Ni-10Cr-8Fe alloy consists of Cr2O3,FeCr2O4 spinel and possibly NiO.Cr2O3 film is formed on Ni-10Cr and Ni-20Cr,but no spinel oxide peak is observed in the SERS spectra.As the Cr concentration increases,the amount of Cr2O3 in the surface film increases but the amount of NiO decreases.