A New Method for Describing the Atomic-scale Structure of Rusts Formed on the Iron Based Alloy Surfaces
A New Method for Describing the Atomic-scale Structure of Rusts Formed on the Iron Based Alloy Surfaces
复制标题
描述铁基合金表面铁锈原子尺度结构的新方法
DOI：
10.2355/isijinternational.43.366
复制
发表时间：
2003
影响因子：
1.8
通讯作者：
Y. Waseda
中科院分区：
文献类型：
--
作者：
Shigeru Suzuki;M. Saito;M. Kimura;Tamaki Suzuki;H. Kihira;Y. Waseda
采用常规X射线衍射和反常X射线散射结合反向蒙特-卡罗模拟技术对Fe、Fe-2%Cr、Fe-3%Ni和Fe-1.6%Cu合金及耐候钢表面锈层的原子尺度结构进行了定量分析。通过过滤这些合金在盐水中的表面上形成的腐蚀产物来制备锈蚀样品。X射线衍射分析表明，锈层主要由γ-FeOOH等羟基氧化铁组成。从常规的X射线衍射和异常X射线散射得到的径向分布函数清楚地表明，在锈的基本本地单元结构是八面体的FeO 6，虽然它可能是扭曲的。通过拟合使用反向蒙特-卡罗模拟技术计算的普通和环境干扰函数来估计铁锈中的真实原子排列。这些结果表明，网络结构由FeO 6八面体单元组成，其畸变程度取决于样品的组成。这些事实表明，锈中的合金元素本身被腐蚀，在形成锈的原子级结构中起着重要作用。
Quantitative structural analysis by conventional X-ray diffraction and anomalous X-ray scattering coupled with the reverse Monte-Carlo simulation technique has been carried out, in order to characterize the atomic-scale structure of rust formed on the surface of Fe, Fe-2%Cr, Fe-3%Ni and Fe-1.6%Cu alloys and a weathering steel. Rust samples were prepared by filtering corrosion products formed on the surface of these alloys in salt water. X-ray diffraction patterns showed that main components of the rust consist of ferric oxyhydroxides such as γ-FeOOH. Radial distribution functions obtained from both conventional X-ray diffraction and anomalous X-ray scattering clearly indicated that the fundamental local unit structure in the rust is the octahedral FeO 6 , although it is likely to be distorted. Realistic atomic arrangements in the rust were estimated by fitting of the ordinary and environmental interference functions calculated using the reverse Monte-Carlo simulation technique. These results provided that the network structure consists of the FeO 6 octahedral units and its distortion depend upon the composition of samples. These facts suggest that alloying elements in the rust, which themselves are corroded, play an important role in forming the atomic-scale structure of the rust.