Electrochemical corrosion behavior of martensitic stainless steel in an oilfield environment

In view of the inherent complexity of the oilfield environment, improving the corrosion resistance of pipeline systems is a crucial factor in ensuring a stable energy supply. Copper as an alloying element has the potential to improve the corrosion resistance of other metal materials. In this study, 11Cr martensitic stainless steel with different copper contents was prepared and tempered at different temperatures to investigate its corrosion properties and corrosion mechanism in oilfield produced fluids. The electrochemical behavior of 11Cr martensitic stainless steel in two kinds of oilfield produced fluid was analyzed utilizing electrochemical testing methods. Electrochemical experiments have demonstrated that the specimen with 0.5 % copper content exhibited the lowest corrosion rate after tempering at 600℃, particularly in polymer flooding produced fluid. Furthermore, the polarization curve and EIS analysis indicated that copper content and tempering temperature exerted a significant effect on corrosion resistance. The result from the surface morphology examination indicate that the dispersed precipitation of copper elements significantly improves the corrosion resistance of martensitic stainless steels.