Process for manufacturing galvannealed steel sheets having high press-formability and anti-powdering property
US5409553A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1992 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Aug 26, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
It is an object to provide a process for manufacturing galvannealed steel sheets having high anti-powdering property as required when they are press formed, and stabilized frictional properties in a coil. Steel sheets are plated in a bath having a low aluminum content, while they have, when entering the bath, a low temperature as defined in relation to the aluminum content of the bath, so that an alloying reaction may be prevented. Then, the sheets are heated for alloying in a high-frequency induction heating furnace so that the sheets leaving the furnace may have a temperature of from over 495.degree. C. to 520.degree. C. to yield galvannealed consisting mainly of a .delta..sub.1 phase. An iron or iron-alloy top coating having an appropriate iron content can be applied onto the plated steel surface to improve its paintability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.