Surface-treated steel sheet for fuel tanks
US10738384B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2016 |
| Grant date | Aug 11, 2020 |
| Priority date | — |
| Expiry date | Dec 31, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12993
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A surface-treated steel sheet for fuel tanks, including a Zn—Ni alloy plating layer on one surface or both surfaces of a steel sheet; and a trivalent chromate covering layer or a chromate-free covering layer on the Zn—Ni alloy plating layer, wherein, in a surface outermost layer of the trivalent chromate covering layer or the chromate-free covering layer, concavities, of which a depth from an arithmetic average height of a cross-sectional curve of the surface outermost layer is more than or equal to 0.1 μm, exist in a proportion of 50 to 1000 concavities/mm2 and at an area ratio of 20 to 80% to a surface area of the steel sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.