Method for manufacturing iron-zinc alloy plated steel sheet having two plating layers and excellent in electropaintability and pressformability
US5316652A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D3/562
- 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: applying an alloying treatment under a temperature of from 420.degree. to 520.degree. C. to a zinc dip-plated steel sheet to form on the surface of the steel sheet an alloying-treated iron-zinc alloy dip-plating layer having on the surface thereof fine irregularities comprising numerous fine concavities and numerous fine convexities; then applying a temper rolling treatment at a reduction rate of from 0.3 to 1.5 to the alloying-treated steel sheet, to level the numerous fine convexities on the surface of the alloying-treated iron-zinc alloy dip-plating layer, so as to form on the surface of the steel sheet the alloying-treated iron-zinc alloy dip-plating layer as a lower layer having the numerous fine concavities on the surface thereof; and then applying an iron-zinc alloy electroplating treatment to the temper rolling treated steel sheet to form, on the alloying-treated iron-zinc alloy dip-plating layer as the lower layer, an iron-zinc alloy electroplating layer as an upper layer. The above-mentioned ir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.