Steel wire for hard drawn spring excellent in fatigue strength and resistance to settling, and hard drawn spring and method of making thereof
US7597768B2 · kind B2 · utility
5Cited by
8References
18Claims
0Family size
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Inventors
Key dates
| Filing date | Mar 26, 2003 |
| Grant date | Oct 6, 2009 |
| Priority date | — |
| Expiry date | Sep 20, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/479
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 μm or more is 5 particles/100 μm2 or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.