The Use of Electrochemical Impedance Spectroscopy Method for Corrosion Resistance Evaluation of 2205 and 410s Stainless Steels in Aqueous Sodium Chloride Solution

This paper investigates the effects of Ta content on the microstructures, hardness and corrosion behavior of as-cast CoCrFeNiTax alloys. The results indicate that the addition of Ta can change the microstructures of these alloys to dual-phased structures (FCC + HCP), as well as increasing their hardness. This study uses constant galvanostatic/potentiometric methods to measure the polarization curves of CoCrFeNiTa0.1, CoCrFeNiTa0.3 and CoCrFeNiTa0.5 alloys in deaerated 1 M sodium chloride solution at different temperatures. Electrochemical impedance spectroscopy is also used to analyze these alloys in sodium chloride solution. The results indicate that the CoCrFeNiTa0.5 alloy has a eutectic structure and the highest hardness. Furthermore, although the CoCrFeNiTa0.5 alloy has the best corrosion resistance, the CoCrFeNiTa0.3 alloy has the best pitting resistance among these alloys.

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Sage Extract as a Natural Source of Corrosion Inhibitor for Tinplate in 3.0 % NaCl

Food Technology and Biotechnology ◽

10.17113/ftb.59.04.21.7026 ◽

2021 ◽

Vol 59 (4) ◽

Author(s):

Maja Dent ◽

Regina Fuchs-Godec

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Sodium Chloride ◽

Impedance Spectroscopy ◽

Corrosion Inhibitor ◽

Chloride Solution ◽

Sodium Chloride Solution ◽

Corrosion Inhibitors ◽

Electrochemical Impedance ◽

Low Cost ◽

Green Inhibitor

Research background. Due to the growing interest and attention of the world towards environmental problems and protection of environment, the worldwide demand for biodegradable and effective corrosion inhibitors for tinplate has grown. Considering the diversity of the structures of polyphenols that are present in sage extract, it represents a promising potential source of low-cost and biodegradable effective green corrosion inhibitors for tinplate in 3.0 % sodium chloride solution which is evaluated in this study. Experimental approach. Tafel polarization and electrochemical impedance spectroscopy (EIS) at 25 °C has been used to evaluate the inhibition action of sage (Salvia officinalis, L.) extract as a green inhibitor for the corrosion protection for tinplate in 3.0 % sodium chloride solution. Results and conclusions. Electrochemical impedance spectroscopy has been used to show that sage extract could serve as an effective inhibitor (90.2 %) for the corrosion of tinplate in 3.0 % NaCl at a concentration of 0.2 mg/L, and temperature of 25 °C. The results obtained from potentiodynamic polarization have revealed that the sage extract inhibitor acts as a mixed type, with inhibition efficiency up to 82.5% and the inhibition efficiencies calculated from EIS are in close agreement with those results. FTIR results indicated that the inhibitory effect of the sage extract is due to the presence of a passivation layer on the tinplate surface, which consists of organic compounds such as polyphenols. It has been confirmed by these results that the sage extract is more efficient at inhibiting the corrosion of tinplate at a concentration of 0.2 mg/L than in higher concentrations. Also, it exhibits good inhibitive performance for tinplate in 3 % sodium chloride solution. Novelty and scientific contributions. The exceptional corrosion potential of sage extract opens a door for its use and revalorization as a green corrosion inhibitor in the food industry.

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Chloride ion storage performance of polyaniline/graphene nanocomposite in aqueous sodium chloride solution

Materials Research Bulletin ◽

10.1016/j.materresbull.2021.111209 ◽

2021 ◽

pp. 111209

Author(s):

Tiantian Zhu ◽

Hui Kong ◽

Tianchen Xia ◽

Yuyin Shen ◽

Yingchun Miao ◽

...

Keyword(s):

Sodium Chloride ◽

Chloride Solution ◽

Sodium Chloride Solution ◽

Chloride Ion ◽

Aqueous Sodium Chloride Solution ◽

Aqueous Sodium ◽

Storage Performance ◽

Ion Storage ◽

Graphene Nanocomposite

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DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

Canadian Journal of Chemistry ◽

10.1139/v60-208 ◽

1960 ◽

Vol 38 (9) ◽

pp. 1488-1494 ◽

Cited By ~ 6

Author(s):

E. J. Bounsall ◽

W. A. E. McBryde

Keyword(s):

Aqueous Solution ◽

Nitric Acid ◽

Sodium Chloride ◽

Hydrochloric Acid ◽

Chloride Solution ◽

Sodium Chloride Solution ◽

Silver Content ◽

Aqueous Sodium Chloride Solution ◽

Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

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