3Cr管线钢CO_2腐蚀实验研究  

EXPERIMENTAL STUDY OF CO_2 CORROSION OF 3Cr PIPE LINE STEEL

作　　者：郭少强[1] 许立宁[1] 常炜 密雅荣[3] 路民旭[1] 

机构地区：[1]北京科技大学新材料技术研究院,北京100083 [2]中海石油研究总院,北京100027 [3]西北农林科技大学,杨凌712100

出　　处：《金属学报》2011年第8期1067-1074,共8页Acta Metallurgica Sinica

基　　金：国家科技重大专项资助项目2008ZX05056-02~~

摘　　要：用线性极化法(LPR)研究了3Cr管线钢在高温高压CO_2腐蚀环境下的腐蚀速率,利用电化学阻抗谱(EIS)结合SEM与EDS研究了腐蚀不同时间的腐蚀产物膜.利用EIS监测到腐蚀产物膜中出现二次富Cr程度低的内层膜,并对其进行了分析.结果表明,腐蚀产物膜分为向基体内部原位生长的非晶富Cr层与腐蚀后期在其上沉积的FeCO_3晶粒层两部分,腐蚀膜内含Cr化合物的不断富集和致密度的提高,是腐蚀速率持续下降的主因;含Cr化合物的成膜需要一定的Cr^(3+)浓度;由于3Cr管线钢的点蚀源处的局部腐蚀速率较快,导致Cr^(3+)局部富集成膜,使点蚀源内腐蚀产物膜Cr/Fe比远高于周围,从而抑制了蚀坑的发展.Linear polarisation resistance（LPR） was used to trace the corrosion rate of 3Cr pipe line steel during corrosion process.EIS and SEM were used to detect the structure of protective CO_2 corrosion product films.The appearance and evolvement of the loose internal-layer with lower Cr/Fe ration which was observed by SEM,was analyzed by EIS.Amorphous corrosion product film grew from outside to inside with time.The increase of the Cr/Fe ratio and the thickness of the film cause the decrease of momentary corrosion rate.The chromic compound produced by a certainty Cr^（3＋） concentration.When the pitting corrosion suppressed,high corrosion rate in the pit resulted in high Cr^（3＋） concentration which would produce much chromic compound,and in this way,the development of the pit would be prevented.

关 键 词：CO2腐蚀 3Cr管线钢 线性极化电阻 电化学阻抗谱 

分 类 号：TG172.9[金属学及工艺—金属表面处理]