Electrochemical behavior of steel bar in electrolytes: Influence of pH value and cations

Abstract

Steel bar corrosion on electrolytes and the influence of cation were investigated. Three electrolytes of Ca(OH)₂, NaOH and KOH with pH levels of 12.5, 11.5, 10.5, 9.5, 8.5 were prepared, meanwhile, the methods of free corrosion potential and electrochemical impedance spectra (EIS) were used to evaluate the influence of cations on the depassivation of the steel bar in electrolytes. The experimental results indicate that the initial corrosion pH value of the steel bar is influenced by the cation in electrolyte and the influence of K⁺ in electrolyte is the most remarkable, followed by Na⁺ and Ca²⁺. The initial corrosion pH values are 10.5 in KOH electrolyte, 9.5 in NaOH electrolyte and lower than 8.5 in Ca(OH)₂ electrolyte.

Keywords

steel bar corrosion / cation / pH value

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