| Title | In-situ synchrotron XRD studies of CO2 corrosion of carbon steel |
| Publication Type | Conference Paper |
| Year of Publication | 2012 |
| Authors | Ko, M., Ingham B., Laycock N., Burnell J., and Williams D.E. |
| Conference Name | Annual Conference of the Australasian Corrosion Association 2012 |
| Date Published | 2012 |
| Keywords | Anodic dissolution, Anodic potentials, Carbon dioxide, Carbon steel, Corrosion, Dissolution, Dissolution rates, In-situ synchrotrons, Induction periods, Iron ores, Lasers, Saturated solutions, Siderite, Small concentration, Steel, Synchrotrons, X ray diffraction |
| Abstract | In-situ synchrotron x-ray diffraction was used to determine the structure and composition of the surface scale formed on carbon steel in CO2 saturated solutions at 80°C under anodic polarisation. The results showed a significant induction period before siderite precipitation, which directly correlated with a rise in the current density to a point when a sufficiently coherent scale is formed. The addition of small concentrations of MgCl 2 accelerated the scale formation and caused the formation of Fe 2(OH)2CO3 along with siderite. At pH between 4.2 and 6.8 with applied anodic potentials from -700 mV to -600 mV vs. SCE (rest potential (Ecorr) = -775 mV to -725 mV), the anodic dissolution of mild steel is accelerated by decreasing pH. Siderite is precipitated when a critical local supersaturation near the surface is achieved. The onset of siderite precipitation causes local acidification of the solution and accelerates the dissolution rate of the steel until a coherent protective scale is formed. Copyright © (2012) by the Australasian Corrosion Association. |
| URL | http://www.scopus.com/inward/record.url?eid=2-s2.0-84876831388&partnerID=40&md5=1e31f0262d6d1e8ccdee7e9714cd250d |
