Electrochemical impedance spectroscopy analysis of corrosion product layer formation on pipeline steel

EIS analysis of the electrochemical characteristics of the metal–water interface under the effect of temperature

“…Several time-constant characteristics of impedance spectroscopy at different temperatures can be clearly distinguished from the peaks in the phase plot. 31 The phase angle curves in the environments of 20, 10 and 5 °C are similar, the phase angle peaks generated by the relaxation of distilled water (capacitive medium) are all located at 10 4 to 10 5 Hz, and the relaxivity generated by the dissolution reaction and the passivation reaction at the electrode interface peaks at around 10 0 to 10 1 Hz and 10 −2 Hz, respectively. The characteristic frequency values corresponding to the above three time constants shift slightly to the left as the temperature drops, and the extension of the relaxation time of each control process can be judged according to τ = 1/ ω *, 32 where τ is the time constant and ω * is the characteristic frequency.…”

“…Previous studies have derived the base current density formula to fit potentiodynamic current–potential curves to obtain various kinetics parameters. 31 Aiming to establish the relationship between the equivalent circuit model and electrochemical kinetic theory, this study proposes an easy method to calculate kinetic parameters only by the circuit element parameters obtained by electrochemical impedance spectroscopy fitting.…”

Microstructure Characteristics and Corrosion Behavior of Low‐Alloy High‐Strength Steel used for Armor Layer under Exposure to H2S‐Saturated Solution

“…The structural characteristics of the corrosion products, especially the surface morphology, therefore play a vital role in the corrosion behavior. [ 46–48 ] Figure 3 shows the macroscopic surface morphology of the corrosion products formed after different durations of immersion. Figure 3a,b show that two types of surface morphology appeared on the specimen surface after immersion for 24 and 72 h. The partial area of the specimen surface obtained after 24 h of immersion was covered with corrosion products.…”

Eco-Friendly Anticorrosion Superhydrophobic Al2O3@PDMS Coating With Salt Deliquescence Self-Coalescence Behaviors Under High Atmospheric Humidity

“…Figure 5B shows the Bode plots of log |Z| vs. log frequency of the Q235 carbon steel and superhydrophobic Al 2 O 3 @PDMS coating. The impedance modulus data at low frequency (|Z| 0.01 Hz ) are commonly used as an intuitive index of the anticorrosion barrier performance of protective coatings (Mishra et al, 2020;Wiering et al, 2021). According to the Bode plots of log |Z| vs. log frequency, the |Z| 0.01 Hz of the superhydrophobic Al 2 O 3 @PDMS coating is 1.53 × 10 7 Ω•cm 2 , which is four orders of magnitude higher than bare Q235 carbon steel (1.31 × 10 3 Ω•cm 2 ), indicating that the superhydrophobic Al 2 O 3 @PDMS coating can lead to excellent corrosion protection properties.…”