Description / Abstract:
This standard covers the requirements for both one and two side pure
zinc and zinc nickel alloy
electrogalvanized coatings. These coatings are applied to a sheet
steel substrate utilizing an
electroplating process. The substrate may be either cold or hot rolled
low carbon, rephosphorized,
solid solution strengthened, bake-hardenable, high strength low alloy
or dual phase steel.
Additional requirements or agreements shall be specified by the local
business units (e.g., NAO,
Opel ITDC, GM do Brazil, Holden Ltd., etc.)
Material Description. The type of coating and its mass and finish are
specified by suffixes added
to the basic specification number. The first two letters EG will
designate an electrogalvanized
coating. The coating mass for each side is designated by a minimum
value in g/m². Only coating
masses of 47 g/m², 60 g/m² or 70 g/m² for pure zinc,
and 32 g/m² for
zinc-nickel alloy should be used unless materials engineering is
consulted. Other coating masses
shall follow the same designation method. For one side coated coils,
or sheets/blanks the uncoated
side should be free of coating. A residue of 40 mg/m² max. is
permissible. The letter G
designates a pure zinc coating. The letter N designates a zinc-nickel
alloy coating. The first set
of digits along with the letter designation specifies the coating
parameters of the unexposed side.
The remaining designation specifies E (exposed), or U (unexposed) to
depict surface finish.