温度对N80碳钢CO2腐蚀产物膜性能的影响  

EFFECT OF TEMPERATURE ON PROPERTIES OF CO_2 CORROSION SCALE OF N80 CARBON STEEL

作　　者：李党国[1,2] 冯耀荣[2] 白真权[2] 郑茂盛[1] 

机构地区：[1]西安交通大学材料科学与工程学院,西安710049 [2]中国石油天然气集团公司管材研究所,西安710065

出　　处：《中国腐蚀与防护学报》2008年第6期369-373,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：国家重点基础研究发展规划项目(G1999065004);国家自然科学基金(50231020)资助

摘　　要：用电化学阻抗谱技术研究了不同温度下N80油套管钢在饱和CO2模拟地层水中的腐蚀电化学性能,并观察了腐蚀产物膜的形貌。结果表明,中、低温条件下,温度升高,膜的致密性增加,离子在膜内的扩散过程减弱;当温度达到200℃时,扩散阻抗下降,扩散过程变得相对容易。腐蚀产物膜呈双层结构,其厚度随温度的升高而逐渐减小。去除腐蚀产物膜后的试样表面形貌显示,随着温度的升高,腐蚀坑逐渐变小,直至最后转变为均匀腐蚀;当温度达到200℃时,点蚀坑又变大,表明腐蚀有进一步加剧的迹象。The electrochemical properties and microstructures of CO2 corrosion scale formed on N80 carbon steel at 3 MPa and different temperatures in stratum water with saturated CO2 were investigated. The impedance results showed that the compactness of corrosion scale increased and the diffusion process decreased with increasing temperature; when temperature reached to 200 ℃, the diffusion impedance of corrosion scale decreased, indicating that the diffusion of ions in the scale became easy. electrochemical impedance spectrum （SEM） results revealed that the scale is of a double-layer structure, the length of the scale decreased with temperature increasing. Observation of the microstructure of the sample surface after removing the corrosion scale, showed that many big holes existed in the sample surface at low temperature,which became small and finally turned into uniform corrosion with temperature increasing. When temperature reached to 200 ℃ the holes became bigger again, indicating the corrosion extent promoted furthermore.

关 键 词：N80碳钢 电化学阻抗谱 地层水 扩散 

分 类 号：TG172.3[金属学及工艺—金属表面处理]