The Roles of Fluid Hydrodynamics, Mass Transfer, Rust Layer and Macro-Cell Current on Flow Accelerated Corrosion of Carbon Steel in Oxygen Containing Electrolyte

Abstract

The flow accelerated corrosion (FAC) of EH 36 carbon steel in the oxygen containing flowing electrolyte is studied using multi-electrode array arranged in a jet rig system. The FAC of the working electrodes (WEs) under both uncoupled and coupled conditions are investigated in conjunction with computational fluid dynamics (CFD) simulation. Results show that a higher mass transfer rate would lead to a higher FAC rate when the WEs are uncoupled. The rust layer could retard the oxygen diffusion, resulting in the FAC rate decreasing. The mass transfer process and the distribution of the rust layer are significantly influenced by the fluid hydrodynamics. However, when the WEs are coupled together, serious FAC damage would occur on the WEs where lower mass transfer rates are registered. The macro-cell currents would become the main lead of FAC propagation at coupled conditions.