Iron-zinc alloy electro-galvanized steel sheet having a plurality of iron-zinc alloy coatings
US4543300A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1984 |
| Grant date | Sep 24, 1985 |
| Priority date | — |
| Expiry date | Apr 27, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12972
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An iron-zinc alloy electro-galvanized steel sheet having a plurality of iron-zinc alloy coatings, which comprises: at least one iron-zinc alloy coating as the lower layer, formed on the surface of a steel sheet, and at least two iron-zinc alloy coatings as the upper layer, formed on the at least one iron-zinc alloy coating as the lower layer. The ratio of iron content to the coating weight of each of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 15 wt. %, and the total coating weight of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 50 g/m.sup.2 per side of the steel sheet. The ratio of iron content to the coating weight of each of the at least two iron-zinc alloy coatings as the upper layer is over 15 wt. %, the ratio of iron content to the coating weight gradually increases from the innermost coating toward the outermost coating of the at least two iron-zinc alloy coatings as the upper layer, the difference in the ratio or iron content to the coating weight between two adjacent coatings of the at least two iron-zinc alloy coatings as the upper layer is within the range of from 1 to 15 wt.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.