CORROSION BEHAVIOUR OF PIPELINE STEEL IN CO_2 ENVIRONMENT

摘要

The influence of temperature (30-120 deg C) on the corrosion behavior of low carbon pipeline steels in the CO_2 saturated solutions in the closed autoclave system has been studied. At lower temperatures, the surface films have an open porous structure and hence the FeCO_3 film formed dissolved continuously in the CO_2 saturated solution. Between 60 to 90 deg C, the FeCO_3 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 90 deg C, a dense protective FeCO_3 film is formed and the corrosion rate decreases significantly at 120 deg C.