Process for making cold-rolled dual phase steel sheet
US9593399B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2013 |
| Grant date | Mar 14, 2017 |
| Priority date | — |
| Expiry date | Apr 23, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/54
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for manufacturing a cold rolled high strength dual phase steel. The process includes soaking a steel slab within a temperature range of 1200-1300° C., hot rolling the soaked steel slab in a roughing treatment and producing a transfer bar, and hot rolling the transfer bar in a finishing treatment and producing hot rolled strip. The hot rolled strip is cold rolled with at least a 55% reduction in thickness. The cold rolled sheet is intercritically annealed at a temperature between 790-840° C. and rapidly cooled to a temperature between 450-500° C. The rapidly cooled sheet has a ferrite plus martensite microstructure, a 0.2% yield strength of at least 550 MPa, a tensile strength of at least 980 MPa and a total elongation to failure of at least 10%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.