Process for manufacturing bake hardening steel sheet, and steel sheet and parts thus obtained
US7540928B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 2003 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Nov 6, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/06
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention concerns a method for making hardenable steel plates by firing comprising: preparing a steel whereof the composition comprises, expressed in weight percent: 0.03=C=0.06, 0.50=Mn=1.10, 0.08:=Si=0.20, 0.015=Al=0.070, N=0.007, Ni=0.040, Cu=0.040, P=0.035, S=0.015, Mo=0.010, Ti=0.005; provided that it comprises boron in an amount such that 0.64=B/N=1.60 the rest consisting of iron and impurities resulting from production; casting a slab of said steel, then hot rolling of said slab to obtain a plate, the final rolling temperature being higher than the point Ar3; winding said plate at a temperature ranging between 500 and 700° C.; then cold rolling of said plate at a reduction rate ranging between 50 and 80%; continuous annealing heat treatment for a time interval less than 15 minutes; and strain hardening with a reduction rate ranging between 1.25 and 2.5%. The invention also concerns the hardenable plates and the parts obtainable therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.