Zinc coated steel plates coated with a pre-lubricating hydroxysulphate layer and methods for obtaining same
US6528182B1 · kind B1 · utility
12Cited by
2References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 25, 2001 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Jun 25, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention concerns a steel plate coated with a metal layer based on zinc and a zinc hydroxysulphate layer, whereof the surface density of sulphur is more than 0.5 mg/m2. The invention also concerns a method for obtaining said plate by treating a zinc coated sheet metal: either in a highly alkaline sulphate solution under polarization; or in a sulphate solution containing Zn2+ ions without polarization. The hydroxysulphate deposit brings about a pre-lubricating effect applicable to operations for forming sheet metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.