Detecting and monitoring erosion-corrosion using ring pair electrical resistance sensor in conjunction with electrochemical measurements

Abstract

The erosion-corrosion behavior of X65 pipeline steel was studied using a novel designed ring pair electrical resistance sensor (RPERS) array in conjunction with linear polarization resistance (LPR) measurement within a flow loop containing 3.5 wt% NaCl solution with 1 wt% silica sand under 0.1 m/s, 0.5 m/s, 1 m/s, 1.5 m/s flow rates. The initiation of erosion-corrosion could be well captured and the individual contributions of erosion and corrosion on the total metal loss could be accurately measured and evaluated by the sensor system. In combination with computational fluid dynamics (CFD) simulation, the influences of the inhomogeneous distribution of the flow field on the localized erosion-corrosion around the pipe circle was studied. It is found that severe erosion-corrosion prefers to occur around the high sand concentration area under high flow rate conditions. The accuracy of LPR method was studied when localized corrosion appeared on the steel surface. Based on the theoretical derivation and the experimental results, it is found that LPR measurement could effectively reveal the general corrosion rate when the electrochemical kinetic parameters of the anodic and cathodic sites are similar.