Corrosion and control of P110 oil tube steel in CO2-saturated aturated solution

Effects of the temperature, pH value and CO2 partial pressure on the corrosion rate of P110 oil tube steel in CO2-saturated solution were studied by using the weight loss method. The corrosion products formed on P110 steel's surface were observed by scanning electron microscopy (SEM) and their compositions were analysed by X-ray diffraction (XRD). The results indicate that temperature significantly influences the corrosion rate, which maximises at 80 degrees C under a CO2 partial pressure of 0.8 MPa. The corrosion rate increases along with the increase of CO2 partial pressure and decrease of the pH value of the solution. The protective film (FeCO3) can be formed under the high temperature and high pH value of the solution. The inhibition of an imidazoline derivate was also discussed in this paper.