Abstract
Processes for the zinc-iron alloy electroplating on steel sheets, and the properties of these alloy electroplated steel sheets in comparison with the zinc electroplated steel sheets, were described.
(1) The composition of zinc-iron alloy electroplating was varied with the bath compositions and plating conditions, the iron content of the plating increased with the increase of iron content to zinc content in the bath, the plating current density and the pH of the plating bath, and decreased with the raise of bath temperature.
(2) Zinc-iron alloy electroplated steel sheets showed the good spot weldability according to the increase of the iron content of the plating, and this tendency was remarkable when the welding current was low.
(3) Zinc-iron alloy electroplated steel sheets with the iron content of 7% to 25% showed the best corrosion resistance and also the red rust produced on the plating was least.
(4) Zinc-iron electroplated steel sheets on which the electropainting was applied after phosphate treatment also showed better corrosion resistance than the zinc electroplated steel sheets according to the increase of iron content of plating.
