Corrosion behaviour of pipeline steel in CO2 environment

The influence of temperature (30-120degreesC) on the corrosion behavior of low carbon pipeline steels in the CO2 saturated solutions in,the closed autoclave system has been studied. At lower temperatures, the surface films have an open porous structure and hence the FeCO3 film formed dissolved continuously in the CO2 saturated solution. Between 60 to 90degreesC, the FeCO3 film accumulated: more in the outer part, which is more porous, less dense, and nonprotective in nature and hence the corrosion rates of samples increase with temperature. Incontrast, above 90degreesC, a dense protective FeCO3 film is formed and the corrosion rate decreases significantly at 120degreesC