Method for manufacturing iron-zinc alloy plated steel sheet having two plating layers and excellent in electropaintability and press-formability
US5225067A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | Oct 23, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D5/36
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for manufacturing an iron-zinc alloy plated steel sheet having two plating layers and excellent in electropaintability and press-formability, which comprises the steps of: passing a steel sheet through a zinc dip-plating bath to form a zinc dip-plating layer on at least one surface of the steel sheet; then, heating the steel sheet, on which the zinc dip-plating layer has been formed, to alloy the zinc dip-plating layer and the surface portion of the steel sheet, so as to form, on the surface thereof, an alloying-treated iron-zinc alloy dip-plating layer as a lower layer having a plating weight of from 30 to 120 g/m.sup.2 per surface of the steel sheet; then, passing the steel sheet through an acidic plating bath for 1 to 5 seconds without electrifying same to dissolve the surface portion of the alloying-treated iron-zinc alloy dip-plating layer, so as to form numerous fine jogs on the surface thereof; and then, electroplating the steel sheet in an iron alloy acidic electroplating bath to form an iron alloy electroplating layer as an upper layer, having a plating weight of 1 to 10 g/m.sup.2 per surface of the steel sheet, on the alloying-treated iron-zinc alloy dip-plating …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.