一种新型锈蚀转化剂的作用机理研究

Converting Mechanism of a New Type of Rust Converter

采用SEM和AFM技术研究了锈蚀转化涂层形貌的演化过程,利用XPS技术研究了锈蚀转化剂对Fe3+的转化能力,通过能谱分析和红外光谱技术,研究了锈蚀转化剂中的关键组分,从而推断出锈蚀转化剂的反应机理。结果表明,当锈蚀转化剂涂覆在锈蚀层上,其表面发生了一些化学反应。在72 h后,锈蚀转化涂层由两相融为均匀相,并且表面粗糙度降低。在此过程中,锈蚀层中Fe3+部分转化为Fe2+。生成的Fe2+和剩余的Fe3+则与锈蚀转化剂中的无机阴离子和单宁酸形成稳定的Fe PO4,Fe3(PO4)2,Zn3(PO4)2和单宁酸铁络合物构成的保护膜。

The surface morphology of rust converter coating was firstly studied using scanning electron microscopy(SEM) in conjunction with atomic force microscopy(AFM). Then, the conversion of Fe3 +in rust- converting coating, which was induced by rust converter, was investigated by XPS technology. Finally, the key compositions of rust converter were characterized by energy dispersive spectrum technology(EDS) and Fourier transform infrared spectroscopy(FTIR) in order to study the converting mechanism of rust converter. It was found that some chemical reactions occurred in rust converter coating after rust layer had been coated with rust converter. After 72 h, the rust converter coating has eventually developed into homogeneous phase, and surface roughness decreased. During this conversion, parts of Fe3 +transformed into Fe2 +, forming stably inorganic salt film composed of iron phosphate, zinc phosphate and ferrous oxides. At the same time, some organic compounds, for example tannic acid, can complex with Fe3 +, and mixed with inorganic salt film,forming stably protective film.