Method for fabricating steel sheet for press hardening, and parts obtained by this method
US9845518B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2017 |
| Grant date | Dec 19, 2017 |
| Priority date | — |
| Expiry date | May 31, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention provides a rolled steel sheet, for press hardening, for which the chemical composition includes, with contents expressed by weight, 0.24%≦C≦0.38%, 0.40%≦Mn≦3%, 0.10%≦Si≦0.70%, 0.015%≦Al≦0.070%, 0%≦Cr≦2%, 0.25%≦Ni≦2%, 0.015%≦Ti≦0.10%, 0%≦Nb≦0.060%, 0.0005%≦B≦0.0040%, 0.003%≦N≦0.010%, 0.0001%≦S≦0.005%, 0.0001%≦P≦0.025%, it being understood that the titanium and nitrogen content satisfy: Ti/N>3.42, and that the carbon, manganese, chromium and silicon content satisfy:with the chemical composition optionally including one or more of the following elements: 0.05%≦Mo≦0.65%, 0.001%≦W≦0.30%, 0.0005%≦Ca≦0.005%, with the remainder made up of iron and inevitable impurities coming from preparation. The sheet includes a nickel content Nisurf at any point of the steel near the surface of said sheet over a depth Δ, such that Nisurf>Ninom, where Ninom designates the nominal nickel content of the steel, and such that Nimax designates the maximum nickel content within Δ:and such that:with the depth Δ expressed in microns and the Nimax and Ninom contents expressed in percentages by weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.