P110钢CO_2腐蚀产物膜的XPS分析

XPS Analysis of CO_2 Corrosion Product Scales on P110 Steel

为了确定CO2腐蚀产物膜的组成及不同层次结构中成分和含量的差异,采用P110钢在高温高压腐蚀静态釜中制备CO2腐蚀产物膜,利用SEM观察了腐蚀产物膜的表面和断面形貌,结合XRD分析结果,通过XPS研究了两层结构膜的化学组成差异。结果表明,腐蚀产物膜断面呈现双层结构;膜层的主要成分是FeCO3,还有少量的CaCO3和铁的氧化物,但内层CaCO3较多且夹杂着Fe3C和单质Fe,外层氧化物稍多;通过内外层Ca2+含量差异推断出内层腐蚀膜优先形成。

In order to confirm the composition of CO2 corrosion product scale and the difference of both component and the content between various layers of the scale, autoclave was employed to prepare the scales on P110 steel exposed to carbon dioxide corrosion. The surface and cross-section morphology were observed with scanning eleetron microscope （SEM）, and the difference between surface and inner in chemical composition was analyzed with X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD） used adjectively. The results show that the cross-section of the corrosion product scales of P110 steel is with double-layer structure, and there are mainly FeCO3 and a little of CaCO3 with ferreous oxides in two layers structure of the scale. The amount of CaCO3 in surface layer is less than one in inner layer, but the oxides are slight more than that in inner layer including a little intermixtures of Fe and Fe3C. It is concluded from the difference of Ca^2＋ ion between the surface and the inner that the inner corrosion scale produces first on P110 steel in corrosion process.