Corrosion and control of P110 oil tube steel in CO 2 -saturated solution

Abstract

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°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.