Widely used by industry in general, and automotive manufacturers in particular, zinc nickel gives sacrificial protection to the underlying iron or steel, that is the zinc corrodes in preference to the substrate. This has the additional benefit that steel exposed at cut or abraded areas will not easily rust. This coating can be produced from acid or alkali solutions, the most popular now becoming the alkali as it is easier to control, is more ductile, gives a more consistent alloy and more even thickness than the acid solution.
|Passivate Coating||Salt Spray (hrs)|
|Cr6+||White Rust||Red Rust|
|Blk Chromate + top||Free||240||1200|