Niobium- and titanium-based coating for the protection of carbon steel SAE 1020 against corrosion

• Published in: Anti-corrosion methods and materials 2022-06, Vol.69 (4), p.426-433
• Main Authors: Helleis, Rodrigo, Maia, Guilherme Arielo Rodrigues, Castro, Eryza Guimarães de, Berbel, Larissa Oliveira, Costa, Isolda, Banczek, Everson do Prado
• Format: Article
• Language: English
• Subjects: Ammonium; Ammonium compounds; Analytical methods; Anodic polarization; Carbon steel; Carbon steels; Chelating agents; Coated electrodes; Corrosion; Corrosion prevention; Corrosion resistance; Crystal structure; Crystals; Electrochemical impedance spectroscopy; Electrochemistry; Electrode polarization; Electrodes; Electron microscopy; Environmental impact; Environmental law; Immersion coating; Immersion plating; Low carbon steels; Mechanical properties; Niobium; Open circuit voltage; Phosphating (coating); Precursors; Protection; Protective coatings; Resins; Scanning electron microscopy; Spectroscopy; Spectrum analysis; Surface treatment; Titanium; Toxicity; X-ray diffraction
• ISSN: 0003-5599; 1758-4221
• DOI: 10.1108/ACMM-10-2021-2561

Purpose The purpose of this paper is to evaluate the protection against corrosion of carbon steel SAE 1020 promoted by a niobium- and titanium-based coating produced from a resin obtained by the Pechini method. Design/methodology/approach A resin was prepared with ammonium niobium oxalate as niobium precursor and K2TiF6 as titanium precursor. Carbon Steel SAE 1020 plates were dip coated in the resin and calcinated for 1 h at 600 ºC. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to characterize the coating morphologically and structurally. Open circuit potential, electrochemical impedance spectroscopy, anodic potentiodynamic polarization and scanning vibrating electrode technique were used to evaluate the corrosion protection of the coating. Findings The electrochemical analyses evidence slight protection against corrosion of the coating by itself; however, the needle-like crystal structure obtained may potentially provide a good anchorage site, suggesting the coating could be used as a pretreatment that may present similar application to phosphating processes, generating lower environmental impacts. Originality/value Due to increasingly restrictive environmental laws, new environmentally friendlier surface treatments must be researched. This paper approaches this matter using a combination of niobium- and titanium-based coating, produced by a cleaner process, the Pechini method.