Evaluation of Corrosion and Erosion-Corrosion Behavior of X65 Pipeline Steel in Flowing CO2-Saturated Electrolyte

Abstract

In this study, the corrosion and erosion-corrosion behaviors of X65 pipeline steel in the flowing CO2-saturated electrolyte were electrochemically studied using a rotation disk system. The results showed that the accumulation of the Fe3C layer in the electrolyte without sand particles enhanced the cathodic reaction, increasing the corrosion rate. The increase in flow velocity facilitated the rapid accumulation of a thick Fe3C layer, which linearly increased the corrosion rate with increasing rotation speed. The sand impacts removed the corrosion product layer and broke the exposed Fe3C network, resulting in a negative synergy of erosion-enhanced corrosion. The erosion-corrosion negatively affected ferrites compared with the pearlites in an electrolyte containing sand due to the weaker erosion resistance.