The Effect of Flowing Velocity and Impact Angle on the Fluid-Accelerated Corrosion of X65 Pipeline Steel in a Wet Gas Environment Containing CO2

This study investigated the effect of flowing velocity and impact angle on the fluid-accelerated corrosion (FAC) of X65 pipeline steel in a wet CO2-containing environment by corrosion morphology analysis, electrochemical measurement, and hydromechanical numerical analysis. It has been found that the corrosion behavior was controlled by the ion diffusion rate and shear stress due to the flowing gas. With an increase in the flowing velocity, the pitting corrosion initially decreased and then increased when the flowing velocity exceeded 14 m/s; this increase is caused by the augmentation of shear stress. When the impact angle decreased, the position of serious corrosion gradually moved outwards.