High-strength cold-rolled steel sheet and method for manufacturing the same (as amended)
US10174396B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 2015 |
| Grant date | Jan 8, 2019 |
| Priority date | — |
| Expiry date | Jul 24, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength cold-rolled steel sheet has a chemical composition containing, by mass %, C: 0.15% or more and 0.30% or less, Si: 0.8% or more and 2.4% or less, Mn: 2.4% or more and 3.5% or less, P: 0.08% or less, S: 0.005% or less, Al: 0.01% or more and 0.08% or less, N: 0.010% or less, Ti: 0.002% or more and 0.05% or less, B: 0.0002% or more and 0.0050% or less, and the balance being Fe and inevitable impurities, a microstructure including ferrite having an average grain diameter of 3 μm or less and a volume fraction of 5% or less (including 0%), retained austenite having a volume fraction of 10% or more and 20% or less, martensite having an average grain diameter of 4 atm or less and a volume fraction of 20% or less (including 0%), and the balance including bainite and/or tempered martensite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.