High-strength, high-toughness steel plate and method for producing the same
US10640841B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2016 |
| Grant date | May 5, 2020 |
| Priority date | — |
| Expiry date | Aug 19, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-strength, high-toughness steel plate having excellent surface properties and a high absorbed energy includes, by mass %, C: 0.03% to 0.08%, Si: 0.01% to 0.50%, Mn: 1.5% to 2.5%, P: 0.001% to 0.010%, S: 0.0030% or less, Al: 0.01% to 0.08%, Nb: 0.010% to 0.080%, Ti: 0.005% to 0.025%, and N: 0.001% to 0.006%, and further includes at least one selected from Cu: 0.01% to 1.00%, Ni: 0.01% to 1.00%, Cr: 0.01% to 1.00%, Mo: 0.01% to 1.00%, V: 0.01% to 0.10%, and B: 0.0005% to 0.0030%, with the balance being Fe and unavoidable impurities. In a surface portion and a central portion in the thickness direction, the area fraction of Martensite-Austenite constituent is less than 3% and the area fraction of bainite is 90% or more, and in the central portion in the thickness direction, the average particle size of cementite in bainite is 0.5 μm or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.