Ferrous product having an alloy coating thereon of Al-Zn-Mg-Si Alloy, and method
US4401727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1982 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Jun 23, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A coated ferrous article with improved properties, e.g., improved overall corrosion resistance and good appearance. The article has a ferrous substrate and a ductile, adherent, corrosion resistant alloy coating metallurgically bonded to the substrate. The alloy coating has a thin intermetallic alloy layer intermediate the substrate and an alloy overlay. The alloy overlay consists essentially of, by weight, magnesium from 3% to 20%, silicon from 3% to 15%, balance aluminum and zinc, where the ##EQU1## is between 1 and 1.5. The metallurgical structure of the overlay is a mixture of (1) cored aluminum-rich dendrites having dendrite arm spacings (DAS) of less than 10.mu., (2) zinc-rich interdendritic regions, and (3) intermetallic phases of zinc, aluminum, magnesium and silicon. The article may be produced by hot dip coating a ferrous substrate in a molten metal bath of the above composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.