chromate passivated zinc coating 1

[rubepierre]

anyone who can explain bleached/unbleached chromate pasivated zinc coating,please help...seems as if too many words are used to describe something not as complex as it sounds...
Thank You (rubepierre)

 

[CoryPad]

I have never heard of bleached or unbleached versions of this coating.

As for the rest, it is a zinc coating deposited either electrolytically or mechanically which is then treated with a chromate ion containing solution that results in an outer conversion layer. This layer contains hexavalent and trivalent chromium ions which improve corrosion resistance of the coating.