A chromate-free black colored steel sheet “ECO FRONTIER Z1,”
one of the distinctive products of JFE Steel, with black appearance, high corrosion
resistance, high heat absorption/radiation property and EMI shielding performance
has been developed. The ECO FRONTIER Z1 consists of (1) a black colored layer
formed on the surface of the Zn-Ni alloy electroplated steel by anodic treatment,
and (2) a chromate-free organic-inorganic composite film. The ECO FRONTIER Z1
has an excellent heat absorption/radiation property with its high heat emissivity.
Spot welding can be applied on ECO FRONTIER Z1 with its good conductivity, and
it has been used for the parts of electrical appliances, office equipments, and
car audio equipments, which require groundability and EMI shielding performance.