High strength hot rolled steel sheet having tensile strength of 780 MPa or more
US10400316B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2014 |
| Grant date | Sep 3, 2019 |
| Priority date | — |
| Expiry date | Jan 19, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/004
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength hot rolled steel sheet with good formability, which has good magnetic properties, excellent punchability, and a tensile strength of 780 MPa or more. The high strength hot rolled steel sheet having a chemical composition containing C: 0.070% to 0.140%, Si: 0.10% to 1.00%, Mn: 1.00% to 1.80%, P: 0.050% or less, S: 0.0050% or less, N: 0.0080% or less, Al: 0.010% to 0.100%, Ti: 0.050% to 0.150%, and the remainder composed of Fe and incidental impurities, on a percent by mass basis, and 95% or more of bainite microstructure on a volume fraction basis, wherein carbides constituting 80% or more of total precipitation carbides are dispersed at grain boundaries of bainitic ferrite constituting the bainite microstructure and 80% or more of total precipitation carbides have particle grain sizes of 20 to 300 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.