A Kinetic Model for CO[sub 2] Corrosion of Steel in Confined Aqueous Environments

Abstract

A kinetic model of the physicochemical processes occurring during the corrosion of steel covered by a thin water film exposed to a CO2 atmosphere is proposed. This model explains theoretically the unusual physicochemical behaviors generally observed in such confined corrosive media: Fe(II) supersaturations, low corrosion rates, high pH values, and their respective dependence on the electrolyte film thickness. More quantitatively, the model predictions agree well with pH and corrosion rate measurements performed in environments similar to the annulus space of flexible pipelines.

Development and evaluation of miniature electrodes for electrochemical measurements in a CO2 top of line corrosion environment

“…Important semi-empirical models include those of Pots & Hendriksen (2000), who proposed the so-called 'super-saturation' model which accounted for the competition between scale formation rate and the condensation rate. The model of Vitse et al (2003), which combined a mechanistic model for film-wise condensation with a semiempirical corrosion model, was later extended by Remita et al (2008) to take account for FeCO3 film formation by incorporating a coverage factor into their analysis. Nyborg & Dugstad (2007) developed a semi-empirical correlation for TLC rate that accounts for water condensation rate, FeCO3 solubility and a super-saturation factor based on the concept that TLC is limited by the amount of Fe that can be dissolved in the thin condensate film.…”

Corrosion mechanisms in aqueous solutions containing dissolved H2S. Part 2: Model of the cathodic reactions on a 316L stainless steel rotating disc electrode

“…As in the case of CO 2 [23], it is not postulated that these reactions always stand at thermodynamic equilibrium. It could thus be necessary to consider the chemical kinetics expressions:…”

Hydrogen uptake and diffusivity in steel armor wires with different chemical composition, carbide distribution, grain size, and degree of deformation

“…The resulting exposure to corrosive media can lead to corrosion and hydrogen embrittlement (HE) of the tensile wires. [1][2][3][4] In this regard, both corrosion and cathodic protection (when the outer shielding is damaged) may introduce atomic hydrogen to the wires.…”

“…The resulting exposure to corrosive media can lead to corrosion and hydrogen embrittlement (HE) of the tensile wires. [ 1–4 ] In this regard, both corrosion and cathodic protection (when the outer shielding is damaged) may introduce atomic hydrogen to the wires. Several incidents of brittle fractures and severe corrosion attacks of flexible pipe steel armor wires have been reported [ 5–7 ] and the failure mechanism can be complex.…”