Cold rolled steel sheet and galvanized steel sheet having strain age hardenability and method of producing the same
US7067023B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2003 |
| Grant date | Jun 27, 2006 |
| Priority date | — |
| Expiry date | Sep 18, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An object of the present invention is to provide a cold-rolled steel sheet and an alloyed hot-dip galvanized steel sheet in which tensile strength is effectively increased by press forming and heat treatment while maintaining excellent deep drawability in press forming. Specifically, a steel composition contains less than 0.01% of C, 0.005 to 1.0% of Si, 0.01 to 1.0% of Mn, 0.005 to 0.050% of Nb, 0.005 to 0.030% of Al, 0.005 to 0.040% of N, 0.0005 to 0.0015% of B, 0.05% or less of P, and 0.01% or less of S, the balance substantially composed of Fe, in which the following equations (1) and (2) are satisfied:N%≧0.0015+14/93.Nb%+14/27.Al%+14/11.B% (1)C%≧(12/93).Nb% (2)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.