Electrochemical Techniques for Corrosion and Tribocorrosion Monitoring: Methods for the Assessment of Corrosion Rates

Abstract

The corrosion mechanism taking place in an aqueous phase with or without mechanical contact is electrochemical in nature. The electrochemical signal is one of the primary sources of information that relates to behavior in potential, current, and electrical charge of a corroding electrode. It arises from processes that cause corrosion and other electrochemical reactions. In a sliding contact in an ionic electrolyte medium, electrochemistry is more likely to interfere with the tribological behavior of tribocorrosion systems. In recent years, attempts by researchers have been made to control the material loss by electrochemical methods for various engineering systems. Applied online for monitoring in-situ uniform, localized, galvanic, or more forms of corrosion, such techniques are very convenient means to measure corrosion rate of materials. Such methods can also be used in different ways to evaluate their ability to protect materials (as inhibitors, protective layers, coatings). In this chapter, theoretical and experimental applications, fundamental aspects, limits of the electrochemical techniques for corrosion, and tribocorrosion monitoring are presented. Standards developed, so far, by various standardization organizations are reported. Fundamentals of traditional and advanced corrosion methods are described, focusing on their advantages, i.e. sensitivity to low corrosion rates, short experimental duration, and well-established theoretical understanding.

Electrochemical Impedance Spectroscopy for the Measurement of the Corrosion Rate of Magnesium Alloys: Brief Review and Challenges

“…The typical impedance spectra of Mg/Mg alloys and the equivalent circuit used to fit the EIS experimental data are shown in Figure 6. The simplest Nyquist plot reveals one semicircle (Figure 6a), which may correspond to a corrosion process under activation control [45]. For analysis, the capacitive arc was simulated by a simple Randles equivalent circuit, consisting of the charge transfer resistance (R2) in parallel with the double layer or oxide film capacitance (C1) in series with the solution resistance (R1) [47,48] (Figure 6a).…”

“…The EIS technique has the ability to study high-impedance systems, such as coatings and linings, high-purity water, and organic coating/metal systems or corrosion in a low-conductive solution [45].…”

Study of laser directed energy deposition of Inconel 625 and austenitic steel

“…I corr can be determined from the Tafel curve by extrapolating the cathodic and anodic curves. The current density of the intersection of the curves gives the I corr value [28]. E w is given by the following equation [29]:…”

Técnicas experimentais e teóricas aplicadas ao estudo de inibidores orgânicos de corrosão em meio ácido

“…Em resumo, as curvas de polarização potenciodinâmica (CPP) são as representações gráficas da relação entre o potencial e a corrente, de uma interface (Berradja, 2019), podendo ser usada para determinar o potencial de corrosão e a taxa de corrosão do metal em determinadas condições. Na Figura 5 são representados estes parâmetros.…”