Campus Units
Aerospace Engineering, Chemical and Biological Engineering, Materials Science and Engineering, Mechanical Engineering, Ames Laboratory
Document Type
Article
Publication Version
Accepted Manuscript
Publication Date
4-17-2020
Journal or Book Title
Electrochimica Acta
First Page
136232
DOI
10.1016/j.electacta.2020.136232
Abstract
Pipeline steels exhibit intergranular corrosion (IGC) and stress corrosion cracking at active dissolution potentials in carbonate-bicarbonate solutions. The evolution of electrochemical behavior of API X70 pipeline steel during active dissolution in 1 M NaHCO3 was investigated by electrochemical impedance spectroscopy (EIS). Electrochemical modeling of EIS revealed that the metal rate is limited by slow diffusion of CO3−2 ions through a porous precipitated corrosion product layer to the steel surface. Further, the porosity of the carbonate layer decreases over time as its thickness increases, both factors contributing to a strongly suppressed corrosion rate due to impeded CO3−2 diffusion. Decreasing steel corrosion rates with time in carbonate-bicarbonate solutions can be understood on this basis. Growth of the carbonate layer at the steel-carbonate interface intensifies tensile wedging stress in corroded grain boundaries, thereby facilitating intergranular crack initiation.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Copyright Owner
Elsevier Ltd.
Copyright Date
2020
Language
en
File Format
application/pdf
Recommended Citation
Mishra, Pratyush; Yavas, Denizhan; Bastawros, Ashraf F.; and Hebert, Kurt R., "Electrochemical impedance spectroscopy analysis of corrosion product layer formation on pipeline steel" (2020). Aerospace Engineering Publications. 164.
https://lib.dr.iastate.edu/aere_pubs/164
Comments
This is a manuscript of an article published as Mishra, Pratyush, Denizhan Yavas, Ashraf F. Bastawros, and Kurt R. Hebert. "Electrochemical impedance spectroscopy analysis of corrosion product layer formation on pipeline steel." Electrochimica Acta (2020): 136232. DOI: 10.1016/j.electacta.2020.136232. Posted with permission.