Corrosion inhibition of pure Mg containing a high level of iron impurity in pH neutral NaCl solution. (September 2018)

• Record Type: Journal Article
• Authors: Yang, Junjie; Blawert, Carsten; Lamaka, Sviatlana V.; Yasakau, Kiryl A.; Wang, Li; Laipple, Daniel; Schieda, Mauricio; Di, Shichun; Zheludkevich, Mikhail L.
• Is Part Of: Corrosion science. Volume 142(2018)
• Page Start: 222
• Page End: 237
• Publication Date: 2018-09
• Subjects: Pure magnesium -- Iron impurity -- Iron re-deposition -- Corrosion inhibitor; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.07.027
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Three high effective corrosion inhibitors are proposed for pure Mg containing a high level of Fe impurity. Suppression of Mg dissolution or cathodic hydrogen evolution are defined as inhibition mechanisms for the chosen inhibitors. Complex(es) can be formed between cathodic inhibitor molecule and Fe 2+ /Fe 3+ impeding the re-deposition of Fe onto Mg surface. Abstract: Three sodium salts of organic acids (2, 5-pyridinedicarboxylic, 3-methylsalicylic and fumaric) were studied as corrosion inhibitors for pure magnesium containing a high level (342 ppm) of Fe impurity. The inhibition effect of the three inhibitors was evaluated by means of hydrogen evolution, electrochemical and surface analysis techniques. Significant reduction in corrosion rate was revealed for of the tested inhibitors in pH neutral NaCl electrolyte. 2, 5-pyridinedicarboxylate and fumarate showed the effects characteristic for mixed-type inhibitors, while 3-methylsalicylate performed more as cathodic inhibitor, complying with the iron re-deposition model, where the electrochemical activity of iron-rich particles was effectively inhibited.