Turbulent Flow Effect on Corrosion of API X80 Steel: Cathodic Kinetic Analysis

Abstract

This work presents the influence of turbulent flow on corrosion kinetics of API X80 steel immersed in synthetic seawater at room temperature and atmospheric pressure. In order to control the turbulent flow conditions, a rotating cylinder electrode (RCE) was used. Different rotation speed were studied: 0 (or static conditions), 1000, 2000, 3000, 4000, 5000 and 7000 rpm. The electrochemical techniques used in the corrosion study were cathodic polarization curves and total polarization curves, using a conventional three electrode cell. The results of cathodic kinetic analysis show that the turbulent flow has influence at all rotation speeds, that is to say, the corrosion process is controlled by a mass transfer process associated with the oxygen diffusion from the bulk electrolyte to metal surface. In addition, the corrosion rate shows a strong increase as the rotation speed of the RCE increases and consequently increasing the Reynolds number.