High strength cold rolled steel sheet having excellent non-aging property at room temperature and suitable for drawing and method of producing the same
US5356494A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1992 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Apr 24, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/002
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a high strength cold rolled steel sheet having excellent non-aging property at room temperature and excellent drawability, said steel sheet having a dual-phase structure composed of a high-temperature transformed ferrite phase and a low-temperature transformed ferrite phase having high dislocation density. The invention also relates a high strength cold rolled steel sheet having excellent non-aging property at room temperature and bake hardenability, as well as excellent drawability. This steel sheet is produced by preparing a hot-rolled steel sheet, cold rolling the hot-rolled steel sheet at a rolling reduction not smaller than 60%, annealing the cold rolled steel sheet at a temperature which is not lower than the .gamma. transformation start temperature but below the A.sub.c3 transformation temperature, and cooling the annealed steel sheet at a rate not smaller than 5.degree. C./sec but not greater than 100.degree. C./sec.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.