Process for dezincing galvanized steel
US5779878A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 1996 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Jul 17, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25F5/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A process for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75.degree. C. and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (i) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (ii) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (iii) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (iv) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.