Method for producing high strength steel sheet excellent in formability
US8262818B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2011 |
| Grant date | Sep 11, 2012 |
| Priority date | — |
| Expiry date | Apr 8, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high strength steel sheet excellent in formability which has a chemical composition in mass %: C: 0.03 to 0.20%, Si: 0.005 to 0.3%, Mn: 1.0 to 3.1%, P: 0.001 to 0.06%, S: 0.001 to 0.01%, N: 0.0005 to 0.01%, Al: 0.2 to 1.2%, Mo≦0.5%, and the balance: Fe and inevitable impurities, with the proviso that the values of mass % for Si and Al satisfy the following formula (1):(0.0012×[objective value of TS]−0.29−[Si])/2.45<Al<1.5−3×[Si] (1)wherein [objective value of TS] represents a design strength value for the steel sheet in an Mpa unit, and has a metal structure containing ferrite and martensite. The above high strength steel sheet is also excellent in formability and the capability of being chemically treated and that of being hot-dip zinc sheeted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.