Influencing Factors of Cathodic Disbonding of 3PE Anti-Corrosion Layer in Pipelines

The cathodic disbondment accelerated test of various influencing factors of 3PE anti-corrosion layer was carried out, and the influence of various factors on the cathodic disbonding of 3PE anti-corrosion layer was obtained by peeling distance and analytic hierarchy process. The results show that in the environmental parameters, the salt content of solution, the concentration of chloride ions, and the damage area of the anti-corrosion layer had little effect on the cathodic disbonding of 3PE anti-corrosion layer; increasing the negative potential would increase the linearity of the peeling distance, and 3PE anti-corrosion layer had the smallest cathodic separation distance in the near-neutral solution. The peeling distance increased with the increase of soil moisture content, and when it reached saturation, the peeling distance was almost unchanged. Among the processing parameters, lower anchor depth and higher surface dust degree would promote the cathodic disbondment, and the increase trend of cathodic disbonding distance was proportional to the thickness of epoxy underlayer. The influence of processing parameters on cathodic disbondment was much greater than that of environmental parameters.