학술논문

Study of Polarization Characteristics of Corrosion Films on Magnesium in Sulfate-Containing Electrolytes
Document Type
article
Source
Applied Sciences, Vol 10, Iss 4, p 1406 (2020)
Subject
magnesium
corrosion
film
electrolyte
voltammetry
corrosion current
corrosion rate
Technology
Engineering (General). Civil engineering (General)
TA1-2040
Biology (General)
QH301-705.5
Physics
QC1-999
Chemistry
QD1-999
Language
English
ISSN
2076-3417
Abstract
In this article, the results of studying the polarization characteristics of magnesium covered with corrosion film in aqueous solutions of MgSO4 and Na2SO4 are presented. The absence of a corrosion-free magnesium surface was shown; in this connection, it was proposed to interpret the larger values of Tafel’s coefficients obtained in the experiment from the point of view of limiting the electrochemical process by charge transfer in the film phase. Charge transfer in corrosion films obeys the regularities of particle movement in high electric fields, and it is not only cationic. According to the impedance measurements, the resistance of the oxide and hydroxide layer of the magnesium-based corrosion film in the studied solutions was calculated. The largest contribution to the restriction of charge transfer in the initial stages of corrosion is made by a dense primary film defining the polarization resistance. Correlation of transfer parameters in high electric fields with thickness and resistance of corrosion film was demonstrated.