CO_2腐蚀环境中温度对5Cr钢腐蚀性能的影响

Effect of Temperature on Corrosion Resistance of 5Cr Steel in Carbon Dioxide Corrosion Environment

模拟塔里木油田现场环境,利用高温高压实验设备辅以失重法,研究了CO2腐蚀环境中温度对油、套管钢5Cr钢腐蚀速率的影响。采用扫描电镜(SEM)、电子能谱(EDS)和X射线衍射(XRD)等方法对试样表面腐蚀产物的形貌及成分进行了分析。结果表明:5Cr钢的平均腐蚀速率随温度的升高而增大,90℃时到达最大值,温度继续升高平均腐蚀速率降低。各种温度下,均没有局部腐蚀发生。所有温度条件下,腐蚀产物均为FeCO3,并且腐蚀产物膜中出现了Cr的富集现象。

The effect of temperature on corrosion resistance of 5Cr steel in CO2 corrosion environment was investigated in high temperature and pressure autoclave by simulating the downhole environment of Tarim oil field,and the corrosion rate was measured by the weight loss method.The corrosion product was analyzed by SEM,EDS and XRD.The results showed that the corrosion rate of 5Cr increased with the temperature.The corrosion rate was maximum when the temperature was 90 ℃,and then decreased with the increasing of temperature.The pitting corrosion was not discovered at all temperatures.When the temperature was lower than 180 ℃,the corrosion product was mainly composed of FeCO3.Cr element was enriched in the corrosion product.