Development and Implementation of a Predictive Model for Flow

Development and Implementation of a Predictive Model
for Flow Influenced Corrosion
KEVIN L. HEPPNER (; 306-966-4770)
RICHARD W. EVITTS (; 306-966-4766)
JOHN POSTLETHWAITE (; 306-966-4768)
Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive,
Saskatoon, SK, Canada, S7N 5A9
Corrosion problems of industrial relevance are often fully or partially induced by
turbulent flow. For example, a flowing aqueous carbon dioxide solution in contact with
mild steel pipe can strip the protective crystalline FeCO3 film in regions of high
turbulence intensity. These turbulent regions, created near flanges, orifices, gaskets, and
other impedances to flow, cause localized shrinkage of the mass transfer boundary layer
thereby increasing the transport rate of cathodic reagents to the metal surface. Previous
theoretical studies of flow influenced corrosion have assumed convection and diffusion
as the sole transport mechanism. A new transport equation, applicable to a wide range of
metals immersed in selected electrolytes, has been developed to more accurately predict
the corrosion rate by incorporating additional effects of electrochemical potential. The
focus of this paper is the development and algorithmic implementation of the model.
Key words: flow influenced corrosion, turbulent flow, mass transfer, boundary layer,
turbulence intensity