Funct. Mater. 2020; 27 4: 730-735.
Electrochemical analysis of corrosion process of steel bar in fluid simulating porous concrete
College of information engineering, Dalian Ocean University, 116023 Dalian, China
Steel bar and concrete are the most commonly used materials in the construction industry, but the corrosion of steel bar has always been an unavoidable and urgent problem in the industry. The method of adding 0.12 mol chloride ion to a fluid simulating porous concrete with a pH value of 12.6 was used in the experiment. By analyzing the change of corrosion potential during steel bar erosion, the whole corrosion process was divided into four processes: passivation, depassivation, corrosion stabilization and corrosion deterioration; the potentiodynamic polarization curves, electrochemical impedance spectroscopy and their parameters were analyzed. According to the Nyquist impedance spectra of corrosion state and different equivalent circuits, the rules of passive film impedance, charge transfer resistance and double-layer capacitance on the surface of steel bar during the whole corrosion process were obtained.
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