管线钢在湿气介质中的H_2S/CO_2腐蚀行为研究

Study On H_2S/CO_2 Corrosion Behavior of Pipeline Steel in Wet Gas

利用高温高压反应釜模拟高含硫气田H2S/CO2共存环境,在流动湿H2S/CO2介质中进行腐蚀实验,辅以SEM,EDS和XRD,探讨了湿气介质中高H2S分压对API-X52和API-X60管线钢H2S/CO2腐蚀行为的影响。两种钢在湿气介质中的腐蚀速率均随H2S分压的升高而增加,X60腐蚀速率略高于X52,随着H2S分压由0.15MPa增至2.0MPa,腐蚀形态由全面腐蚀趋向局部腐蚀,腐蚀过程由H2S控制,腐蚀产物以四方晶系的FeS1-x(Mackinawite)为主。X60钢表面出现氢鼓泡,内部发生氢致开裂。

Flowing wet gas environments containing H2S/CO2 were simulated in a high temperature and high pressure autoclave. Corrosion behaviors of API-X52 and API-X60 pipeline steels were investigated with Scanning Electron Microscopy （SEM） and X-ray Diffraction methodology （XRD）. Effects of high H2S partial pressure on corrosion rate and products were discussed. Corrosion rates of both steels increased with the H2S partial pressure increasing in wet gas, and the corrosion rate of X60 was appreciably higher than that of X52. Localized corrosion was obviously observed when the H2S partial pressure up to 2.0 MPa. The corrosion process was controlled by H2S and mackinawite （FeS1-x） was the dominant corrosion product. Hydrogen blistering and hydrogen-induced cracking were also occurred in X60 in wet gas.