Method for manufacturing a high strength steel product and steel product thereby obtained
US11371109B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 2015 |
| Grant date | Jun 28, 2022 |
| Priority date | — |
| Expiry date | Oct 21, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for manufacturing a steel product includes providing a heated steel starting product at a temperature between 380° C. and 700° C., having a metastable fully austenitic structure, with a specified composition. Then the starting product is hot formed at a temperature between 700° C. and 380° C., with a cumulated strain εb between 0.1 and 0.7, in at least one location of the heated steel starting product, to obtain a fully austenitic hot-formed steel product; quenched by cooling the product down, at a cooling rate VR2 superior to the critical martensitic cooling rate, to a quenching temperature QT lower than Ms in order to obtain a structure containing between 40% and 90% of martensite, the rest of the structure being austenite; then maintained at, or reheated up to a holding temperature PT between QT and 470° C. and holding the product at the temperature PT for a duration Pt between 5 s and 600 s.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.