3D Finite Element Model for Simulation of Mechanical and Electrochemical Effects on Corrosion Defect of Pipeline

This paper deals with the effects of mechanical and electrochemical interactions on the corrosion defect of a pipeline of material grade X100. The pipeline is subjected to tensile strains from the soil and internal pressure in near-neural pH solution. The key idea of this paper is the introduction of newly 3D finite element model for the prediction of coupled mechanical and electrochemical effects on corrosion behavior of the pipeline instead of 2D finite element models commonly used in the literature. The model combines cylindrical metals, electrolyte and electrochemical interface kinetics coupled within mechanical tensile strain induced by soil movement. The finite element simulation of corrosion defect of the pipeline under mechanical and electrochemical effects is performed by utilizing COMSOL MULTIPHYSICS 6.2 software. The simulated parameters covering the stress distribution, corrosion potential, and anodic and cathodic current densities as a function of the size defect and longitudinal tensile strain generate by the soil motion. The developed 3D finite element model is sufficiently reliable to predict the corrosion phenomenon on pipelines under mechanical conditions.