Development of a New Electrodepostion Process for Plating of Low Carbon Steel with Zn-Ni Alloys

Zn-Ni plating process was developed by controlling and optimizing Zn and Ni contents in the final deposit on low carbon steel surface . The selected system was considered as a replacement for cadmium and chromium plating systems . Zinc-Nickel alloy was deposited  on carbon steel from ZnO, NiSO₄.6H₂O, NaOH and C₄H₁₃N₃ as (chelating agent) , by using potentiodynamic technique . Electrochemical and surface analysis  indicated that the deposition took place with the formation of γ phase for zinc-nickel alloy.
The above mentioned coating showed high hardness , smooth, uniform and fine-grain deposit as well as  superior corrosion resistance against sulfuric acid and  NaCl environments .