Abrasion resistances of CO₂ corrosion scales formed at different temperatures and their relationship to corrosion behaviour

Abstract

The abrasion resistances of CO₂ corrosion scales formed on API P110 grade carbon steel at different temperatures and CO₂ corrosion behaviour of P110 carbon steel have been investigated utilising weight loss method, scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that as the film forming temperature increased, the abrasion rate of CO₂ corrosion scales increased firstly and then decreased, the variation trend was similar to that of the corrosion rate, and the maximal abrasion rate was present at 70°C rather than 100°C, at which the maximal corrosion rate was obtained and CO₂ corrosion scales were loose and porous and were composed of FeCO₃, Fe₃C and CaCO₃. The abrasion resistances of CO₂ corrosion scales formed at 100°C was reinforced by the sand particles embedded easily in the loose and porous layer, together with a very hard residual skeleton, Fe₃C. In addition, CaCO₃ was worn out easily and substituted by SiO₂ during abrasive wear.

Keywords:

• CO₂ corrosion
• Corrosion scales
• P110 tubular steel
• Abrasion resistance
• SEM
• XRD

Acknowledgements

Dr. Launch Scientific Research Project of Xi’an Shiyou University (2012BS001) and Key Laboratory Opening Fund of Corrosion and Protection of Tubular Goods Research Center of China National Petroleum Corporation are gratefully acknowledged.