High tensile cold rolled steel sheet and high tensile hot dip galvanized steel sheet having improved stretch flanging property and process for producing same
US5074926A · kind A · utility
5Cited by
2References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | Dec 24, 1991 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12799
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high tensile cold rolled steel sheet improved in stretch flanging property, containing 0.03% to 0.15% by weight of C, 0.05% or less by weight of Si, 0.5% to 1.2% by weight of Mn, 0.005% to 0.045% by weight of Nb, and 0.10% or less by weight of Al, the remainder being iron and unavoidable impurities, and the steel sheet having a uniform and fine recrystallized ferrite structure having a mean grain diameter of 20 .mu.m or less and an area fraction of 95% or more having improving ductility and a process for its preparation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.