Study of the corrosion properties of zinc–nickel alloy electrodeposits before and after chromating

In this study, corrosion behavior of zinc–nickel alloy electrodeposits on steel sheets has been investigated using the neutral salt spray test. The performance of the coatings with various nickel contents (up to 28 wt.%) was compared with electrodeposited zinc coating. The results show that the corrosion resistance of zinc–nickel alloy coatings is superior to that of pure zinc coating and the zinc–13 wt.% nickel gives the best protection. The corrosion behavior of chromated zinc–nickel alloy coatings was also studied. The results show that chromate conversion coating increases the corrosion resistance significantly (up to 3–4 times), and the best corrosion resistance is achieved by chromating of zinc–13 wt.% nickel alloy coating.