The Effects of Metal Finishing on the Appearance of Painted Galvanized Steel

Nitrogen finished galvanized steel and other grades of zinc coated steels with little or no zinc-iron alloy layer have been found to accept normal metal finishing techniques without adversely affecting their pretreating or painting characteristics. The finished surface is comparable in appearance to a painted cold rolled steel surface.

The durability and corrosion resistance of the painted metal finished surface from which all zinc has been removed is equivalent to that of painted cold rolled steel.

Grades with appreciable zinc-iron interfacial alloy in the coating micro-structure can be a problem when the alloy is exposed by metal finishing. Iron-zinc surfaces have a tendency to cause cratering in electrocoat primers.