Corrosion of API X80 Steel Immersed in Seawater: Application of Electrochemical Noise technique

摘要

In this work the corrosion kinetics of X80 steel immersed in synthetic seawater was analyzed using the electrochemical noise technique in static condition at room temperature and atmospheric pressure. An arrangement of three electrodes was used in an electrochemical cell, with two nominally identical working electrodes (X80 steel) and a saturated calomel electrode (SCE) as reference one. The results obtained were used to calculate the localization index (LI), which indicated that the corrosion process has a localized character. The optical micrographs confirmed the attack morphology of the corrosion process. Also, the corrosion rate values for X80 steel obtained from Noise Resistance (Rn) increase and decrease as exposure time elapses. The above is attributed to the rupture and subsequent regeneration of the corrosion products film adsorbed onto the metal surface.