Corrosion rates under charge-conservation conditions

Laboratory and numerical corrosion experiments impose an electric potential on the metal surface, differing from natural corrosion conditions, where corrosion typically occurs in the absence of external current sources. In this work, we present a new computational model that enables predicting corro...

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Detalles Bibliográficos
Autores: Hageman, Tim, Andrade, Carmen, Martínez-Pañeda, Emilio
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/427757
Acceso en línea:https://hdl.handle.net/2117/427757
https://dx.doi.org/10.1016/j.electacta.2023.142624
Access Level:acceso abierto
Palabra clave:Corrosion
Charge conservation
Electrolyte
Finite element method
Oxygen
Hydrogen
Àrees temàtiques de la UPC::Enginyeria dels materials::Degradació de materials
Descripción
Sumario:Laboratory and numerical corrosion experiments impose an electric potential on the metal surface, differing from natural corrosion conditions, where corrosion typically occurs in the absence of external current sources. In this work, we present a new computational model that enables predicting corrosion under charge-conservation conditions. The metal potential, an output of the model, is allowed to change, capturing how the corrosion and cathodic reactions must produce/consume electrons at the same rates, as in natural conditions. Finite element simulations are performed over a large range of concentrations and geometric parameters. The results highlight the notable influence of the charge-conservation assumption and pioneeringly quantify corrosion rates under realistic conditions. They further show: (i) the strong coupling between the corrosion rate and the hydrogen and oxygen evolution reactions, (ii) under which circumstances corrosion pits acidify, and (iii) when corrosion is able to become self-sustained lacking oxygen.