Effect of magnetic field on the electrochemical corrosion behavior of X80 pipeline steel

Abstract

• The role of magnetic fields on corrosion was elucidated. • Parallel magnetic fields have a greater effect on corrosion than perpendicular fields. • Lorentz force under parallel magnetic field facilitates mass transfer process. Oilfield pipelines of long-term operations often subject to magnetic leak detection, and then the residual magnetic field (MF) after detection may have an impact on the pipeline's corrosion behavior. In this paper, weight-loss and electrochemical experiments were used to explore the influence of MF on the corrosion behavior of X80 pipeline steel. And the mechanism of the effect of magnetic field on corrosion was examined by COMSOL multi-physics field simulation software. The results showed the parallel MF has a significant effect on corrosion compared to the vertical MF. The Lorentz force under a perpendicular magnetic field is parallel to the material surface, which does not change the concentration gradient at the material surface. In contrast, the Lorentz force under a parallel magnetic field accelerates the transfer of corrosive ions in the liquid phase to the material surface, which leads to an increase in the corrosion rate. This is more significant when the parallel MF strength increased. The findings of this study inform the comprehension of the corrosion failure behavior of pipeline steel under the effect of MF.