Plating has a number of
applications such as to harden, to
improve wear, to improve paint adhesion
ect., however corrosion resistance is
probably the most common application.
Standard steel can be plated in a
variety of substances ranging from zinc,
to cadmium, to nickel, to chrome.
Zinc plating provides excellent
resistance against oxidation on
steel by forming a barrier around the
part and acting as a sacrificial anode
if the barrier is damaged.
Cadmium plating is still used in
aerospace applications because of
its excellent corrosion resistance and
it is even compatible with aluminum.
Nickel plating offers a much shinier and
harder finish, but is generally more
expensive than zinc and has a lower
corrosion resistance. Chrome plating
gives one of the brightest finishes, but
a part often has to be polished and
buffed before plating because the
plating process does not cover up any of
the impurities in the metal.