Electrochemical characterization of electrodeposited chromium and nickel-chromium layers on a steel substrate

• Published in: Journal of applied electrochemistry 1988-09, Vol.18 (5), p.739-744
• Main Authors: BODIN, A, OVERKAMP, P. J. B, DE WIT, J. H. W
• Format: Article
• Language: English
• Subjects: Applied sciences; Corrosion; Corrosion mechanisms; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Metals, semimetals and alloys; Metals. Metallurgy; Physics; Specific materials
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/BF01016901

Chromium was deposited on steel specimens and on electroplated steel specimens covered with a Watts Ni layer. The influence of the substrate and of the crack pattern of the electrodeposited Cr layer on the passivation and the reactivation behaviour has been studied by means of potentiodynamic polarization curve measurements and cyclic voltammetry. In the results of the above mentioned electrochemical measurements a strong influence of the substrate was found for a cracked Cr layer deposited on the steel specimen and for a cracked Cr layer deposited on a 30 mu m Watts Ni layer. No influence of the substrate was found in the case of a crack-free Cr layer deposited on the steel substrate or on a Watts Ni layer. It is thus possible to determine whether the Cr layer is cracked or crack free by recording a polarization curve or a cyclic voltammogram for a Cr-plated system. A mechanism is proposed for the passivation and repassivation of cracked Cr layers electrodeposited on a steel substrate or on a Watts Ni layer. 12 ref.--AA