Method for the manufacturing of liquid metal embrittlement resistant galvannealed steel sheet
US11654653B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 2018 |
| Grant date | May 23, 2023 |
| Priority date | — |
| Expiry date | Feb 17, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D7/0614
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention relates to a method for the manufacture of a galvannealed steel sheet including the steps of A.) coating of the steel sheet with a first coating consisting of nickel and having a thickness between 150 nm and 650 nm, the steel sheet having the following composition in weight percentage 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb≤0.5%, B≤0.010%, Cr≤1.0%, Mo≤0.50%, Ni≤1.0%, Ti≤0.5%, the remainder of the composition is made up of iron and inevitable impurities resulting from the elaboration, B.) annealing of the coated steel sheet being annealed at a temperature between 600 to 1200° C., C.) coating of the steel sheet obtained in step B.) with a second coating based on zinc and D.) an alloying heat treatment to form a galvannealed steel sheet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.