Galvannealed steel sheet and method for producing the same
US10745775B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 2016 |
| Grant date | Aug 18, 2020 |
| Priority date | — |
| Expiry date | Mar 26, 2037 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel sheet for galvannealed steel contains, by mass %, C: 0.25 to 0.70%, Si: 0.25 to 2.50%, Mn: 1.00 to 5.00%, Al: 0.005 to 3.50%, P: 0.15% or less, S: 0.03% or less, N £ 0.02%, O £ 0.01%, and optionally one or more selected from Ti, Nb, V, Cr, Mo, Cu, Ni, B, Ca, REM, Mg, W, Zr, Sb, Sn, As, Te, Y, Hf and Co, a balance being Fe and impurities. The microstructure consists of, by vol. %, retained g: 10.0 to 60.0%, high-temperature tempered martensite3 5.0%, low-temperature tempered martensite3 5.0%, fresh martensite £ 10.0%, a: 0 to 15.0%, P: 0 to 10.0%, a balance being bainite. Total volume ratio of tempered martensite and bainite is 30.0% or more, tensile strength is 1470 MPa or more, tensile strength×uniform elongation is 13000 MPa % or more, and tensile strength×local elongation is 5000 MPa % or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.