Electrochemical impedance spectroscopy of iron corrosion in H 2 S solutions - Sorbonne Université Accéder directement au contenu
Article Dans Une Revue Electrochimica Acta Année : 2018

Electrochemical impedance spectroscopy of iron corrosion in H 2 S solutions

Résumé

Corrosion of iron exposed to H2S saturated solution at pH 4 was studied by electrochemical impedance spectroscopy, weight loss coupons and surface analysis. Hydrogen permeation was also used as indirect means of evaluating the intensity of the proton reduction reaction leading to hydrogen entry into the metal. Since corrosion in this type of test solution results in the rapid build-up of a conductive and highly porous iron sulfide scale, a specific contribution of the film has to be considered. An impedance model was thus proposed. The faradaic anodic impedance consists of a two-step reaction with charge transfer and adsorption – desorption. An additional contribution, associated with the conductive and highly porous iron sulfide film was added in parallel. This contribution, mostly visible in the 2 low frequency domain, presents a 45° tail associated with a porous electrode behavior. This model was well adapted to describe impedance diagrams measured at various exposure times, up to 620 hours. Charge transfer resistance determined from impedance analysis allowed calculating the evolution with time of the corrosion current density. A very good correlation was found between this corrosion current density and the hydrogen permeation current density. As expected in our experimental conditions, a permeation efficiency close to 100 % is demonstrated. Corrosion rate of 490 µm/year was measured by weight-loss specimens, confirming the validity of the impedance analysis, which resulted in a calculated corrosion rate of 530 µm/year.

Domaines

Chimie
Fichier principal
Vignette du fichier
Deffo_Electrochim-Acta_2018_manuscript.pdf (816.52 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01836251 , version 1 (12-07-2018)

Identifiants

Citer

Martien Duvall Deffo Ayagou, Mai Tran, Bernard Tribollet, Jean Kittel, Eliane Sutter, et al.. Electrochemical impedance spectroscopy of iron corrosion in H 2 S solutions. Electrochimica Acta, 2018, 282, pp.775 - 783. ⟨10.1016/j.electacta.2018.06.052⟩. ⟨hal-01836251⟩
195 Consultations
591 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More