High strength cold rolled steel sheet and method for manufacturing the same
US6494969B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2000 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Aug 3, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0236
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention relates to a very low C—Nb cold rolled steel sheet giving 340 to 440 MPa of tensile strength. For example, the cold rolled steel sheet consists essentially of 0.0040 to 0.01% C, not more than 0.05% Si, 0.1 to 1.0% Mn, 0.01 to 0.05% P, not more than 0.02% S, 0.01 to 0.1% sol.Al, not more than 0.004% N, 0.01 to 0.14% Nb, by weight, and balance of substantially Fe and inevitable impurities, and has not less than 0.21 of n value calculated from two points (1% and 10%) of nominal strain determined by the uniaxial tensile test, and relates to a method for manufacturing the cold rolled steel sheet. The present invention provides a high strength cold rolled steel sheet for automobile exterior panels having excellent combined formability, resistance to embrittlement during secondary operation, formability at welded portions, anti-burring performance, good surface appearance, and uniformity of material in a coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.