Ultra-low carbon steel composition, the process of production of an ULC BH steel product and the product
US6623691B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 2000 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Dec 22, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D8/0478
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention describes an ultra-low carbon bake hardenable galvanized or galvannealed steel product, having a higher yield strength at the temperature of the molten zinc bath while maintaining a low yield strength and excellent bake hardening properties in a skinpassed condition, BH0 being higher than 35 MPa and BH2 higher than 40 MPa (GI) and BH0>20 MPa and BH2>30 MPa (GA), as well as having a superior paint appearance after stamping and painting. The content in the steel composition of the Ti is comprised between 3.42 N and 3.42 N+60 ppm for a fixed nitrogen content (N), and the Nb-content, comprised between 50 ppm and 100 ppm, is fixed so that no substantial precipitation of niobium carbides will occur during the process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.