Internal localized corrosion of X100 pipeline steel under simulated flow conditions

Abstract

In this paper, a wire beam electrode (WBE) was used to explore the local corrosion processes of X100 pipeline steel in simulated solution containing HCO3− in static and flow conditions. The results indicated that the WBE's current density mapper was remarkably consistent with the polarization curves. Therefore, WBE is an efficient online corrosion monitoring approach. The WBE discovered undetectable pitting and passivation qualities within the X100 pipeline steel under static conditions. However, the corrosion current density of X100 steel was substantially higher under flow conditions than under static ones. The addition of HCO3− ions significantly decreased the corrosion resistance of the X100 steel. In the 0.3 mol/L HCO3− simulated solution, dynamic corrosion was 92 times faster than static. The corrosion of X100 steel was enhanced by the combined effects of fluid movement and HCO3− ions. Additionally, X100 steel produced significant irregular edge pitting when the critical level of HCO3− was 0.2 mol/L under dynamic conditions, and an erosion theory was proposed to explain this phenomenon.