Electrolyte Composition for Distinguishing Corrosion Mechanisms in Steel Alloy Screening

Abstract

The formation and breakdown of passive layers due to pitting corrosion are a major cause of failure of metal structures. The investigation of passivation and pitting corrosion requires two different electrochemical measurements and is therefore a time consuming process. To reduce time in material characterization and to study the interactions of both mechanisms, here, a combined experiment addressing both phenomena is introduced. In the presented electrolyte the different corrosion mechanisms are distinguished and investigated by cyclic voltammograms and polarization scans. The measurements show a passive area, metastable pit growth, and pitting corrosion as well as repassivation. The pitting corrosion is separated from additional dissolution processes and the standard deviation of the corrosion potential is smaller than in other electrolytes. Both passivation and pitting corrosion can be observed in one measurement without additional corrosion attacks. The deviation between different measurements of the same steel is small; this is helpful for the screening of similar materials.

Descriptors for High Throughput in Structural Materials Development

“…Characteristic values such as the height and position of the oxidation peaks or the passive current density (i pas ) provide information about the passive layer stability and the corrosion resistance. By adding sodium chloride to the electrolyte, additional characteristic values such as the pitting potential can be determined [29]. The peak heights i peak , the passive current densities i pas derived from the CVs and the corrosion current densities i corr , derived from LSV measurements, of both samples revealed differences in the electrochemical behaviors of the steels (Figure 25b).…”

“…and process parameter can be adjusted to investigate different corrosion phenomena. Changes of the characteristic values of linear sweep voltammetry, cyclic voltammetry and impedance spectroscopy can correlate with changes in the micro structure, like phase composition and grain size, and thus mechanical properties on the different scales [28][29][30]. In addition, when heating the samples with the GKZ heat treatment, two endothermic peaks were measured (carbide formation and austenitizing).…”

Stainless Steel Voltammetric Sensor to Monitor Variations in Oxygen and Humidity Availability in Reinforcement Concrete Structures

“…According to Babic and Metikos-Hukovic [ 26 ] and Bösing et al [ 36 ], the peaks observed in Figure 5 a,c during anodic sweeping (P.Ox.) are associated with the electroformation of Fe(OH) 2 layers and their oxidation to form FeOOH layers, while the peaks noted during cathodic sweeping (P.Re.)…”

“…are associated with a reduction in these products. The Fe(OH) 2 and FeOOH layers form on a pre-existing protective Cr 2 O 3 layer [ 26 , 36 ].…”

The influence of microstructure deformation on the corrosion resistance of cold formed stainless steel

“…All potentials in this paper are referred to the Ag/AgCl electrode. The electrochemical measurements, potentiodynamic polarization scans and electrochemical impedance spectroscopy, were done in phosphate buffered saline (PBS) containing 0.2 M NaCl + 0.1 M phosphate buffer solution [17] (pH = 7.5). Before each measurement the working electrodes were wet grinded with SiC grinding paper up to 2000 grid, degreased in ethanol and cleaned in an ultrasonic bath containing deionized water.…”