13Cr油套管钢CO2腐蚀产物膜的能谱分析

利用高温高压釜，模拟油田腐蚀环境条件，采用13Cr油套管钢制备了CO2腐蚀产物膜，借助电子扫描显微镜（SEM）观察了腐蚀膜的表面和横截面形貌，通过X射线能量散射分析（EDAX）、X射线衍射（XRD）和X射线光电子光谱（XPS）等方法测定和分析了腐蚀产物膜的组成，以推测13Cr钢的CO2腐蚀机制。结果表明，13Cr钢在试验条件下以均匀腐蚀形成的CO2腐蚀产物膜具有双层结构；该腐蚀产物膜主要含有Fe、Cr、C和O四种元素；表层主要是粗大松散的FeCO3晶体颗粒堆积而成，内层是细小致密的晶态FeCO3和非晶态的Cr（OH）。微粒构成；内层膜较好的致密性和离子透过选择性是13Cr钢具有较好耐CO2腐蚀性能的主要原因。

Spectral Analysis of CO2 Corrosion Product Scales on 13Cr Tubing Steel

CO2 corrosion product scales on 13Cr tubing steel formed in the simulated corrosion environment of oil field in an autoclave are investigated in the paper. The profiles of the surface and cross-section of the scales were observed by scanning electron microscopy （SEM）, the chemical composition of the scales were analyzed using energy dispersion analyzer of X-ray （EDAX）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） to examine the corrosion mechanism of the 13Cr steel in the simulated CO2 corrosion environment. The results show that the corrosion scales with a double-layer structure are formed by fashion corrosion and consist mainly of four elements, i.e. Fe, Cr, C and O, in which the outer layers are constituted of bulky and incompact crystals of FeCO3, and the inner layers are composed of fine compact crystals of FeCO3 and amorphous Cr（OH）3. Because of the characteristics of compactness and ion permanent selectivity of the inner layers of the corrosion product scales, 13Cr steel is more resistible in CO2 corrosion environment.