Rolled steel bar for hot forging
US9574255B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 2012 |
| Grant date | Feb 21, 2017 |
| Priority date | — |
| Expiry date | Nov 7, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A rolled steel bar has a composition consisting, by mass percent, of C: 0.27 to 0.37%, Si: 0.30 to 0.75%, Mn: 1.00 to 1.45%, S: 0.008% or more and less than 0.030%, Cr: 0.05 to 0.30%, Al: 0.005 to 0.050%, V: 0.200 to 0.320%, and N: 0.0080 to 0.0200%, the balance being Fe and impurities. The contents of P, Ti and O in the impurities are, by mass percent, P: 0.030% or less, Ti: 0.0040% or less, and O: 0.0020% or less. Y1 expressed by the formula <1> is 1.05 to 1.18.Y1=C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V−(5/7)S <1>.C, Si, Mn, Cr, V, and S in the formula represent mass percent of the elements. A hot-forged part having a tensile strength of 900 MPa or higher and a transverse endurance ratio of 0.47 can be obtained by the rolled steel bar.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.