High tensile strength galvanized steel sheets excellent in formability and methods of manufacturing the same
US9458521B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 2014 |
| Grant date | Oct 4, 2016 |
| Priority date | — |
| Expiry date | Jul 2, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A formable galvanized steel sheet includes, in terms of % by mass, 0.05 to 0.3% of C, 0.01 to 2.5% of Si, 0.5 to 3.5% of Mn, 0.003 to 0.100% of P, 0.02% or less of S, 0.010 to 1.5% of Al, and 0.01 to 0.2% in total of at least one element selected from Ti, Nb and V, the remainder being Fe and unavoidable impurities, having a microstructure composed of, in terms of area fraction, 20 to 87% of ferrite, 3 to 10% in total of martensite and residual austenite, and 10 to 60% of tempered martensite, and a second phase composed of the martensite, residual austenite, and tempered martensite having an average crystal grain diameter of 3 μm or less, and having a ratio of absorption energy AE to tensile strength TS (AE/TS) not less than 0.063.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.