Steel sheet
US7252722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2004 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Apr 25, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel sheet containing 0.004 to 0.02% C, 1.0% or less Si, 0.7 to 3.0% Mn, 0.02 to 0.15% P, 0.02% or less S, 0.01 to 0.1% Al, 0.004% or less N, 0.2% or less Nb, by mass %, optionally Ti, Bi or at least one element selected from the group consisting of Cr Mo, Ni and Cu, and the balance being Fe; the Nb content satisfying a formula of(12/93)×Nb*/C≧1.0,wherein Nb*=Nb−(93/14)×N, and wherein C, N and Nb designate the content in mass % of carbon, nitrogen and niobium, respectively; and a yield strength and an average grain size of the ferritic grains which satisfy a formula ofYP≦−120×d+1280,wherein YP designates yield strength in MPa, and d designates an average size of ferritic grains in μm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.