模拟油田现场Cl-/CO2腐蚀环境, 对超级13Cr不锈钢在不同温度下的耐均匀腐蚀及点蚀的性能进行了研究。利用金相、扫描电镜(SEM)、能谱分析(EDS)及X射线衍射(XRD)等方法对试样进行了分析。结果表明, 温度升高, 超级13Cr均匀腐蚀速率增大, 温度升高到150 ℃时, 均匀腐蚀由轻微腐蚀转变成中度腐蚀。在Cl-/CO2腐蚀环境中, 超级13Cr不锈钢极易发生点蚀, 且温度升高, 点蚀程度先加重后减弱, 在120 ℃时, 点蚀坑数量最多, 尺寸最大, 点蚀最严重。XRD结果显示, 所有温度条件下材料均无CO2腐蚀产物FeCO3产生, 超级13Cr不锈钢依靠表面形成的钝化膜抵抗CO2腐蚀。

The resistant to uniform corrosion and pitting corrosion of super 13Cr stainless steel at different temperatures was studied in simulated oil field corrosion environment with Cl- and CO2. The surfaces of specimens were analyzed by metallography, scanning electron microscopy (SEM), energy disperse spectroscopy(EDS) and X-ray diffraction (XRD). The results showed that the uniform corrosion rate increased with the increase of temperature, and slight uniform corrosion turned moderate at 150 ℃. In Cl-/CO2 corrosive environment, pitting corrosion of super 13Cr stainless steel occurred very easily, pitting corrosion rate increased firstly and then decreased when temperature raised, pitting corrosion was the most serious when temperature was 120 ℃. X-ray diffraction showed that there was no CO2 corrosion product at all the tested temperatures, indicating that the CO2 corrosion resistance of super 13Cr stainless depends on the passive film formed on the material surface.