Electrochemical response of micro-alloyed steel under potentiostatic polarization in CO_2 saturated brine

摘要

Corrosion scales were formed on micro-alloyed steel designated as P110X and compared with API 5L X65 in CO2 saturated 3.5 wt% NaCI at 60 degrees C and pH 6.5 using potentiostatic polarization at three different anodic potentials for 24 h. The electrochemical behaviour of the corrosion scales were investigated using EIS and surface analysis techniques. The results revealed that the scales were non-protective demonstrating a decrease in film stability with increase in potential. It was generally observed that due to chemical composition and microstructures API 5L X65 exhibited better general corrosion resistance but showed more prone to pitting corrosion than steel P110X.