纳米晶304不锈钢高温氧化膜中Cr和Mn元素的XPS和UPS表征

XPS and UPS Characterization for Cr and Mn in High-Temperature Oxide Films of Bulk Nanocrystalline 304 Stainless Steel

利用X射线光电子能谱(XPS)和紫外光电子能谱(UPS),对比研究了普通304不锈钢(CP-SS304)和深度轧制技术制备的块体纳米晶304不锈钢(BN-SS304)在900℃空气中氧化24h后形成的高温氧化膜中Cr和Mn元素的结合能、原子百分比、价电子的相互作用和功函数,分析了BN-SS304表面电子结构的特征。结果表明:两种材料氧化膜中Cr元素以Cr3+和Cr0存在,Mn元素以Mn4+和Mn0存在,在不同溅射时间,BN-SS304氧化膜中Cr3+与(Cr3++Cr0)原子百分比和Mn4+与(Mn4++Mn0)原子百分比均低于CP-SS304氧化膜中的比值。两种材料氧化膜中价电子之间的相互作用主要有Mn—O,Cr—O,Mn0(3d和4s)和Cr0(3d和4s)。与CP-SS304相比,BN-SS304氧化膜表面价电子之间的相互作用强,其功函数比CP-SS304提高0.07eV,BN-SS304的耐高温氧化性能增强。

The authors studied the binding energies of valence electrons of two oxide scales,the atomic percentages of Cr and Mn elements in two oxide films,the work function of two oxide films on bulk nanocrystalline 304 stainless steel（BN-SS304） and conventional polycrystalline 304 stainless steel（CP-SS304）.BN-SS304 was prepared by severe rolling technique,and the two oxide films were formed in atmosphere at 900 ℃ for 24 hours oxidation on BN-SS304 and CP-SS304 surfaces.In the two oxide films,Cr and Mn elements exist in the forms of Cr3＋,Cr0,Mn4＋ and Mn0.The atomic percentage ratios of Cr3＋ /（Cr3＋ ＋Cr0） and Mn4＋/（Mn4＋＋Mn0） in the oxide film on BN-SS304 are lower than those in the oxide film on CP-SS304.The interactions of the two oxides and the valence electrons of elements are Mn—O,Cr—O,3d and 4s of Mn0 and Cr0.The binding energies of the valence electrons in the oxide film on BN-SS304 are larger than those in the oxide film on CP-SS304,the work function of the oxide film on BN-SS304 is 0.07 eV larger than that on CP-SS304.