PROCESS FOR PREPARING ZN-FE BASE ALLOY ELECTROPLATED STEEL STRIPS

摘要

Steel strips are electroplated with a Zn-Fe base alloy containing 10 to 30% by weight of iron in a chloride bath which contains zinc and ferrous chlorides to give a total concentration of zinc and ferrous ions of from 1.0 mol/1 to the solubility limit with a weight ratio of Fe2+ /Zn2+ between 0.10 and 0.35, and chloride ions in a total concentration of at least 6.0 mol/l under electrolytic conditions: pH 1.0 - 6.0, current density 80 - 200 A/dm2, and relative flow velocity 30 - 200 m/min. The bath may further contain a polycarboxylic acid such as citric acid and a Zn-Fe-P alloy plating may be deposited when the bath further contains hypophosphorous acid.