利用高温高压反应釜模拟高含硫气田H2S/CO2共存环境,在流动溶液介质中进行腐蚀实验,辅以SEM和XRD,探讨了温度对API-X60管线钢H2S/CO2腐蚀行为的影响。结果表明:随温度的升高X60钢的腐蚀速率先升高后降低,腐蚀形态由局部腐蚀趋于全面腐蚀,高温区有点蚀倾向。低温区形成的腐蚀产物以马基诺矿型晶体(FeS1-X)和FeS单硫化物为主,随温度升高腐蚀产物以层片状马基诺矿型晶体为主,并出现少量磁黄铁矿型(Fe1-XS)晶体;高温区则以磁黄铁矿型晶体为主。低温区腐蚀产物附着力差导致其覆盖率降低,膜层脱落处的阳极反应速率由于膜层覆盖处的阴极效应而加快,使点蚀迅速发展。
Flowing solution environments containing H2S/CO2 were simulated in a high temperature and high pressure autoclave.Corrosion behavior of API-X60 pipeline steels was investigated with scanning electron microscopy(SEM) and X-ray diffraction methodology(XRD).Effects of temperature on corrosion rate and products were discussed.The results show that corrosion rate of X60 steel increases at the beginning and then decreases with temperature increasing,and localized corrosion turns into general corrosion obviously,but pitting is observed at high temperature.Mackinawite(FeS1-X) and FeS composite form as corrosion product in low-temperature condition,with temperature increasing the corrosion products were dominated by lamellar-type Mackinawite crystal and associated with a small amount of Pyrrhotite(Fe1-XS) crystal.However,Pyrrhotite crystal becomes more dominated at higher temperature region.Poor adhesion of corrosion scale leads to a lower covering rate at low temperature.Cathodic effects of scale promote the localized corrosion and a faster anode reaction rate and rapid development of pitting will be achieved without blocked effect.