Insight into the role of silty sand in FeCO3 precipitation on carbon steel during CO2 corrosion: Experiments, theoretical simulation and modelling

The role of silty sand in FeCO3 precipitation on carbon steel during CO2 corrosion is investigated. Silty sand has a decreasing effect on the kinetic constant and activation energy to mitigate FeCO3 formation. This effect is more significant with the increase of silty sand content, FeCO3 supersaturation and temperature. This is because silty sand can adsorb Fe2+, repel CO32- and change ions distribution. A new and ultimately more accurate kinetic model for the corrosion layer accumulation rate of FeCO3 considering the effect of silty sand is proposed and verified, presenting an advancement in the understanding and prediction of CO2 corrosion.