Metal sheet treatment method and metal sheet treated with this method
US11319633B2 · kind B2 · utility
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16Claims
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Key dates
| Filing date | Sep 14, 2018 |
| Grant date | May 3, 2022 |
| Priority date | — |
| Expiry date | Oct 16, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C28/34
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A steel substrate is provided, coated on at least one of its faces with a metallic coating based on zinc or its alloys wherein the metallic coating is itself coated with a zincsulphate-based layer including at least one of the compounds selected from among zincsulphate monohydrate, zincsulphate tetrahydrate and zincsulphate heptahydrate, wherein the zincsulphate-based layer has neither zinc hydroxysulphate nor free water molecules nor free hydroxyl groups, the surface density of sulphur in the zincsulphate-based layer being greater than or equal to 0.5 mg/m2. A corresponding treatment method is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.