High-strength cold-rolled steel sheet and method for producing the same
US10072316B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 2013 |
| Grant date | Sep 11, 2018 |
| Priority date | — |
| Expiry date | May 4, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A cold-rolled steel sheet having a steel composition comprising, by mass %, 0.12% to 0.22% C, 0.8% to 1.8% Si, 1.8% to 2.8% Mn, 0.020% or less P, 0.0040% or less S, 0.005% to 0.08% Al, 0.008% or less N, 0.001% to 0.040% Ti, 0.0001% to 0.0020% B, 0.0001% to 0.0020% Ca, and Fe and incidental impurities. The steel sheet includes a microstructure in which ferrite and bainite phases are 50% to 70% of the total area, the average grain size of the ferrite and bainite phase is 1 to 3 μm, a tempered martensite phase is 25% to 45% of the total area, the average grain size of the tempered martensite phase is 1 to 3 μm, and a retained austenite phase is 2% to 10% of the total area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.