Mitigating flow-assisted corrosion of carbon steel through chemical-mechanical surface engineering

Abstract Flow-assisted corrosion severely limits the lifetime of carbon steel infrastructure in energy systems, yet the role of surface nano-engineering under turbulent conditions remains insufficiently understood. Here, we demonstrate that chemical-mechanical polishing (CMP) can be repurposed as a corrosion-mitigating surface-engineering strategy for carbon steel operating under realistic hydrodynamic regimes. Steel specimens were treated using either silica-based CMP (10%wt SiO₂ with 3%wt H₂O₂) or mechanical abrasion (80 μm grit with H₂O₂) and evaluated under static immersion and turbulent flow (Re > 18,000) across pH 4–7. CMP-treated surfaces exhibited reduced roughness, increased contact angles, and enhanced passive layer stability. Electrochemical polarization revealed significantly lower corrosion current densities for silica-based CMP, with corrosion rates reduced by up to 40% relative to abrasive-treated samples, particularly under acidic conditions. Under dynamic flow, corrosion increased with wall shear stress to a critical threshold (~ 1.75 N mm⁻²), beyond which partial stabilization occurred, indicating a transition from mass-transfer-controlled mechanisms. These findings establish CMP as a scalable surface-engineering approach for mitigating flow-induced corrosion in pipeline environments.