Cold workable steel bar or wire and process
US6488787B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 2001 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Feb 15, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/009
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A machine structural steel bar or wire having a softening degree of at least that of the conventional spheroidization-annealed steel material, excellent hardenability, and improved cold workability,comprising 0.1 to 0.5 wt % of C, 0.01 to 0.15 wt % of Si, 0.2 to 1.7 wt % of Mn, 0.0005 to 0.05 wt % of Al, 0.005 to 0.07 wt % of Ti, 0.0003 to 0.007 wt % of B, 0.002 to 0.02 wt % of N and the balance of Fe and unavoidable impurities, the unavoidable impurities including up to 0.02 wt % of P and up to 0.003 wt % of O, andhaving a microstructure comprising ferrite and spheroidal carbides, the ferritic grain size number according to JIS G0522 of the ferrite being at least No. 8 and the number of the spheroidal carbides per unit area mm2 being up to 1.5×106×C wt %.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.