Electro-co-deposition of corrosion resistant nickel/zinc alloys onto steel substrates
US4282073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 1979 |
| Grant date | Aug 4, 1981 |
| Priority date | — |
| Expiry date | Aug 22, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D5/627
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Novel plating baths and the processes for plating therewith are disclosed which provide corrosion-resistant nickel/zinc alloy coatings containing 13-15 weight/% of nickel for iron or steel substrates. The novel baths have combined nickel and zinc contents in the range of 14 to 24 ounces of metal per gallon with the ratio of nickel to zinc maintained in the range 0.1:0.4. These baths permit satisfactory plating of the alloy to be achieved at current densities in the range 30 to 120 amperes per square foot. At alloy coating thicknesses in the range 0.00005 to 0.0005 inches, a salt spray corrosion resistance in excess of 0.5 hours per microinch is afforded. Additionally, by coating the substrate, before alloy plating, with a substantially pure nickel priming layer, the corrosion resistance rate can be effectively doubled. Apparatus for the continuous plating of the priming layer and the corrosion-resistant alloy layer is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.