Investigation of the passivation process of plastically deformed 316L stainless steel using the high frequency capacitance obtained by EIS

Abstract

This paper was devoted to the study of changes of electrochemical processes (dissolution, passivation) induced by the plastic strain of a 316L austenitic stainless steel in a chloride acid solution (H2SO4 2 M + NaCl 0.5 M). For this purpose, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods have been used for various plastic strain values. In order to only assess the effect of internal stresses created by various dislocation configurations on the dissolution and passivation processes without considering the surface roughness impact, electrochemical experiments have been carried out after polishing the specimen surface. The obtained results show that the electrochemical parameters (corrosion current, activation current peak, high frequency capacitance) change with the increase of plastic strain with the same behavior as the work hardening phases of the material in relation to dislocation pattern.

Production and characterization of AISI 316L stainless steel matrix hybrid composites reinforced with boron carbide and carbon nanotubes

“…It would not be the right approach to draw conclusions about corrosion behaviors of the composites by considering the values of i corr and E corr since the high corrosion resistance of stainless steels is due to their good passivation properties. 47,48

Figure 10.Potentiodynamic polarization curves of the composites with the inset graphs showing the equilibrium and breakdown potentials.

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“…The lower E pit values indicate higher probability of passive film breakdown. 16,48 For this reason, it can be deduced that the pitting corrosion kinetics and passivation stability were negatively affected by the addition of B 4 C and CNT. In addition, the fine precipitates formed together with the increased B 4 C and CNT content made the structure susceptible to microgalvanic corrosion and adversely affected the stability of the passive film.…”

Additive Preparation of Conductive Circuit Based on Template Transfer Process Using a Reusable Photoresist

“…Q 2 represents the capacitive behavior of the electrical double layer at the oxide/electrolyte interface with the PDMS nanolayer as the dielectric, and R 2 represents its resistive behavior. Since the anti-adhesion film mainly affects the electrical behavior of the oxide/electrolyte interface, its capacitance ( C ) can be calculated from Q 2 and R 2 by C = ( R 2 1 – n 2 Q 2 ) 1/ n 2 Figure S4.…”

“…42 Q 2 represents the capacitive behavior of the electrical double layer at the oxide/electrolyte interface with the PDMS nanolayer as the dielectric, and R 2 represents its resistive behavior. Since the anti-adhesion film mainly affects the electrical behavior of the oxide/electrolyte interface, its capacitance (C) can be calculated from Q 2 and R 2 by 57 As a result, the thickness (d) of the antiadhesion film can be obtained from the parallel capacitor equation d = ε 0 εS/C, in which ε 0 represents a vacuum dielectric constant of 8.85 × 10 −14 F/cm, S represents the surface area of anti-adhesion film, and ε represents the relative permittivity of the anti-adhesion film, which was also measured via the EIS test and calculated to be 53.75, as shown in Figure S4.…”

A dense and compact laser cladding layer with solid metallurgical bonding significantly improved corrosion resistance of Mg alloy for engineering applications

“…Anticorrosion performance could be quickly understood from the electrochemical tests of the samples, such as corrosion potential and corrosion current density, that could be determined by the potentiodynamic polarization curves. [33][34][35] Potentiodynamic polarization tests were conducted using a CHI660C three-electrode system, in which a saturated calomel electrode and a platinum electrode were used for the reference electrode and the counter electrode, respectively. Before potentiodynamic polarization tests, the surface of the samples was mechanically polished and then cleaned by ethanol with a purity of 99.7%.…”