Method of producing zinc-chromium alloy plated steel sheet with excellent plating adhesiveness
US5273643A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1993 |
| Grant date | Dec 28, 1993 |
| Priority date | — |
| Expiry date | Apr 13, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D3/565
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention provides a method of producing a zinc-chromium alloy-plated steel sheet having excellent properties such as bare corrosion resistance, corrosion resistance after coating, plating adhesiveness and weldability. The method is characterized by plating the surface of the steel sheet using an acid plating bath containing zinc ion (Zn.sup.2+) and chromium ion (Cr.sup.3+) at a molar concentration ratio of about 0.1.ltoreq.Cr.sup.3+ /(Zn.sup.3+ +Cr.sup.3+).ltoreq.0.9 in a total amount of at least about 0.5 mol/1 within the dissolution range, and about 0.1 to 30 g/1 of at least one nonionic organic additive having at least a triple bond, at a bath temperature of about 25.degree. to 70.degree. C. and a pH of about 1.0 to 4.0 with a current density of about 50 to 200 A/dm.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.