NICKEL-PLATING ON STEEL BY CHEMICAL-REDUCTION

A process has been developed for the production of adherent nickel dep osits of good quality on steel without the use of an electric current. The deposition of nickel is brought about by chemical reduction of a nickel salt with hypophosphites in a hot ammoniacal solution. The reac tion is catalytic and, under the prescribed conditions of concentratio n and pH, no reduction occurs in the solution unless certain metals, s uch as steel or nickel, are introduced into the bath. The reduction th en occurs only at the surface of the immersed metal with the productio n of a coating of nickel of 96 to 97 percent purity.