Steel sheet
US11555234B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 2020 |
| Grant date | Jan 17, 2023 |
| Priority date | — |
| Expiry date | Apr 24, 2040 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D9/46
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The present invention relates to steel sheet realizing both formability and weldability. The steel sheet of the present invention is characterized in that at a surface layer part of a region down to 30 μm from the surface of the steel sheet in the sheet thickness direction, Si oxide grains are present in 3000 to 6000/mm2 in number density, an average of natural logarithms of the particle sizes of the Si oxide grains measured in μm units is −2.0 to −1.2, the standard error of the natural logarithms of the particle sizes is 0.6 or less, and the number of Si oxide grains with deviations of the natural logarithms of the particle sizes from the average larger than 2 times the standard error is 5% or less of the total number of Si oxide grains and at a position of ½ of the thickness of the steel sheet, the number density of the Si oxide grains is 1000/mm2 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.