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Dynamic Polarization Behaviors of Equimolar CoCrFeNi High-Entropy Alloy Compared with 304 Stainless Steel in 0.5 M H(2)SO(4) Aerated Aqueous Solution

Three corrosion potentials and three corrosion current densities are clearly identified before the passivation for both dynamic polarization curves of equimolar CoCrFeNi high-entropy alloy (HEA) and 304 stainless steel (304SS) in 0.5 M H(2)SO(4) aerated aqueous solution, by decomposing anodic and ca...

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Detalles Bibliográficos
Autores principales: Yen, Chao-Chun, Tsai, Ting-Lun, Wu, Bo-Wei, Lo, Yu-Chieh, Tsai, Ming-Hung, Yen, Shiow-Kang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9572144/
https://www.ncbi.nlm.nih.gov/pubmed/36234317
http://dx.doi.org/10.3390/ma15196976
Descripción
Sumario:Three corrosion potentials and three corrosion current densities are clearly identified before the passivation for both dynamic polarization curves of equimolar CoCrFeNi high-entropy alloy (HEA) and 304 stainless steel (304SS) in 0.5 M H(2)SO(4) aerated aqueous solution, by decomposing anodic and cathodic polarization curves. The passivated current density of the former is greater than the latter, compliant with not only the constant of solubility product (k(sp)) and redox equilibrium potential (E(eq)) of each metal hydroxide but also the sequence of bond energy (E(b)) for monolayer hydroxide on their facets derived from the first principle founded on density function theory. However, the total amount of ion releasing from HEA is less than 304SS, since the hydroxide/oxide film formed in the air of the latter containing greater amounts of Fe(Ⅱ) and Mn(Ⅱ) is less stable around corrosion potentials while they are further oxidized into more stable Fe(Ⅲ) and Mn(ⅢorⅣ) with much lower k(sp), leading to the much less increasing ratios of ion releases from 0.25 to 0.6 V.