Thin steel sheet having improved baking hardenability and adapted for drawing and a method of producing the same
US4496400A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1982 |
| Grant date | Jan 29, 1985 |
| Priority date | — |
| Expiry date | Jun 16, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention belongs to a technical field of cold rolled steel sheet. The present invention provides a thin steel sheet suitable to be formed into, for example, an external automotive plate by a method including an appearance-finishing step by bake coating as a final step after drawing (such as press molding). The present invention aims to improve remarkably the yield strength, so-called bake hardenability, of the thin steel sheet in order to produce advantageously a light weight automobile. In addition, the invention aims to compensate advantageously the deterioration of dent resistance of the automobile due to the lowering of the weight, without deteriorating the r value, which is an indication of the press moldability of the thin steel sheet. Accordingly, the present invention discloses an effective compounding amount of Nb, which acts to fix C and N in the steel in the presence of a proper amount of Al, and an annealing condition capable of developing effectively the contribution of Nb.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.