Steel bar
US10131965B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 2014 |
| Grant date | Nov 20, 2018 |
| Priority date | — |
| Expiry date | May 7, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel bar according to one embodiment of the present invention includes predetermined chemical composition, wherein a quenching deflection in a cross section is 1.5 mm or less, wherein Δmax and Δmin is 1.5 mm or less, wherein a structure in a surface layer area includes 10 area % or less of ferrite and a remainder including one or more selected from a group consisting of a bainite and a martensite, wherein an average value of the grain size of a bcc phase in the surface layer area is 1.0 to 10.0 μm, wherein an average value of the grain size of the bcc phase in a center area is 1.0 to 15.0 μm, wherein a hardness of a region of which a depth from the surface is 50 μm is Hv200 to Hv500, and wherein a total decarburized layer thickness DM-T is 0.20 mm or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.