MODELLING OF CARBONATE-BICARBONATE STRESS CORROSION CRACKING OF PIPELINE STEELS

摘要

This project has been concerned with the physical and numerical modeling of the conditions developed under disbonded coatings on steel, with a view to understanding the processes responsible for the conditions that lead to SCC. The physical model (not presented in detail in this paper) has used a polymer film covering a crevice of controlled thickness, with a controlled gas composition (air augmented with additional CO_2) on the exterior of the film. pH has been monitored at locations down the crevice using fibre-optic sensors, and potential has been monitored at the same locations using salt-bridge to conventional reference electrodes. A numerical model of the same system has been developed using a commercial finite element package.