Spot welded joint using high strength and high forming steel and its production method
US10272514B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2014 |
| Grant date | Apr 30, 2019 |
| Priority date | — |
| Expiry date | Feb 2, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/14
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a spot welded joint of at least two steel sheets. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≤C≤0.21%, 4.0≤Mn≤7.0%, 0.5≤Al≤3.5%, Si≤2.0%, Ti≤0.2%, V≤0.2%, Nb≤0.2%, P≤0.025%, B≤0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm2 and containing more than the steel nominal phosphorus content.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.