Diffusion‐controlled Corrosion of Agitated Vessels

Abstract

Introduction Recently, a new type of corrosion inhibitor, namely drag‐reducing polymer, has been developed for combating diffusion‐controlled corrosion of metals subjected to turbulent flow. The mechanism of inhibition is based on the ability of some high‐molecular‐weight polymers to damp turbulent eddies at the corroding surface with a consequent increase in the diffusion layer thickness, across which transfer of dissolved oxygen (depolarizer) or corrosion products takes place. This gives rise to a considerable decrease in the rate of metallic corrosion. Along with corrosion inhibition, the damping of turbulent eddies leads also to a reduction in the friction between the turbulently flowing fluid and the metallic surface, with a consequent decrease in the power required to move the fluids. The majority of previous studies on the use of drag‐reducing polymers as corrosion inhibitors have been conducted using turbulent flow in pipelines.