Hydrogenation and Corrosion Properties of Cr-Ni Coatings from Cr(III) Sulfate- Oxalate Solutions

Issue 4(74) 2014
Pages 62-68

N.A. Polyakov1, D.V. Pautov1, N.A. Vetlugin2

1A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of Russian Academy
of Sciences, Moscow, Russian Federation
2D. Mendeleyev University of Chemical Technology of Russia, Moscow, Russian Federation

Keywords: Cr(III) electrolytes, chromium electrodeposits, chromium coatings, chromium plating, protective ability, corrosion resistance, chromium-nickel alloys, hydrogenation

The effect of the nickel admixture in concentrated sulfate–oxalate chromium plating electrolytes on the chemical composition, hydrogen absorption, and protective ability of the forming coatings is studied. It is shown that addition of nickel ions to electrolyte results in codeposition of chromium and nickel on the cathode with a proportional increase in the content of the latter in the alloy and the external appearance of coatings remains unchanged up to the 12 g/l nickel concentration in the solution. At the same time, the nickel admixture in a concentrated Cr(III) sulfate–oxalate solution produces a negative effect on hydrogen absorption in both the coatings and the steel support. The performed studies of the coatings on steel in a salt spray chamber also demonstrated the negative effect of the nickel
admixture on the protective ability of coatings.