H2S/CO2环境中pH值对腐蚀产物膜以及腐蚀速率的影响  

Effect of pH Value on the Stability of Corrosion Product Film in HS/CO Environment

作　　者：叶帆[1,2] 葛鹏莉[1,2] 许艳艳[1,2] 陈晓华 高多龙[1,2] 陈浩 YE Fan;GE Peng-li;XU Yan-yan;CHEN Xiao-hua;GAO Duo-long;CHEN Hao(Sinopec Northwest Company of China Petroleum and Chemical Corporation,Urumuqi 830011,China;Key Laboratory of Enhanced Oil Recovery in Carbonate Fractured-Vuggy Reservoirs,CNPC,Urumuqi 830011,China)

机构地区：[1]中国石油化工股份有限公司西北油田分公司,新疆乌鲁木齐830011 [2]中国石油化工集团公司碳酸盐岩缝洞型油藏提高采收率重点实验室,新疆乌鲁木齐830011

出　　处：《材料保护》2020年第7期55-60,共6页Materials Protection

摘　　要：为了弄清pH值对钢件在H2S/CO2环境中腐蚀产物的影响,采用宏观观察、扫描电镜(SEM)及能谱(EDS)分析等手段对20钢,L245NCS以及L290 3种材料在CO2和H2S环境中不同pH值下的腐蚀产物进行分析,并分别计算其腐蚀速率。研究发现:随着pH值升高,3种材料的腐蚀速率都发生了下降。当pH=7时腐蚀产物由铁的硫化物和氧化物组成,腐蚀产物膜与基体结合力较强,不容易脱落;当pH=5时,腐蚀产物膜只有一层,含有大量硫化物,腐蚀产物膜与基体结合力较强,也不容易脱落;当pH=3时,腐蚀产物膜中的硫化物含量很低,腐蚀产物颗粒较大,疏松不致密。结果显示,pH值不仅会影响腐蚀产物成分,还会影响腐蚀产物膜的结构,从而对腐蚀速率产生影响。当pH值较高时,腐蚀产物膜分层,且其与基体结合力强,能起抑制腐蚀的作用;当pH低时,腐蚀产物膜与基体结合不紧密,易脱落,从而难以对腐蚀产生抑制作用。In order to make clear the effect of pH value on the corrosion products of steel materials in H2S/CO2environment,the corrosion products of 20 steel,L245NCS,and L290 at different pH values in CO2and H2S environments were analyzed by macroscopic observation,scanning electron microscope (SEM) and energy dispersive spectrometer (EDS),and then their corrosion rates were calculated.Result showed that the corrosion rate of the three materials decreased with increasing pH value.When the pH value was 7,the corrosion product consisted of iron sulfide and oxide,which had a strong binding force with the substrate and could not fall off easily.When the pH value was 5,the corrosion products existed as only one layer of film,which contained a large amount of sulfide.The corrosion product film had a strong binding force to the substrate and was not easy to fall off.When the pH value was 3,the content of sulfide in the corrosion product film was very low,and the corrosion product particles were large and loose.From the experimental results,pH value affected not only the corrosion product composition but also the structure of the corrosion product film,thereby affecting the corrosion rate.At higher pH value,the corrosion product film became layered,and the binding force to the substrate was strong so that it could suppress corrosion well.Nevertheless,when the pH value was lower,the corrosion product film was not tightly bonded to the substrate and easily detached,which hardly suppressed corrosion.

关 键 词：腐蚀产物膜 PH值 腐蚀速率 H2S/CO2环境 钢材 

分 类 号：TG172[金属学及工艺—金属表面处理]