Bake-hardenable cold rolled steel sheet and method of producing same
US6143100A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 29, 1998 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Sep 29, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0436
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A bake hardenable cold-rolled steel sheet and a method for producing the steel sheet are provided, wherein the steel sheet includes carbon in a range of about 0.003-0.1 wt. %, with the amount of carbon in solution being about 3-30 ppm, and the steel is substantially free of Ti, Nb, and V, which are otherwise commonly employed in producing low-carbon bake hardenable cold-rolled steel. The method includes a two stage batch or box anneal, a first stage of which is an intercritical batch anneal at a temperature between the A.sub.1 and A.sub.3 temperatures, and a second, subcritical batch anneal at a temperature below the A.sub.1 temperature and above 900.degree. F., with a slow controlled cooling from the intercritical temperature to the subcritical temperature, and from the subcritical temperature to ambient temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.