| (19) |
 |
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(11) |
EP 2 123 784 A8 |
| (12) |
CORRECTED EUROPEAN PATENT APPLICATION |
|
published in accordance with Art. 153(4) EPC |
| (15) |
Correction information: |
|
Corrected version no 1 (W1 A1) |
| (48) |
Corrigendum issued on: |
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31.03.2010 Bulletin 2010/13 |
| (43) |
Date of publication: |
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25.11.2009 Bulletin 2009/48 |
| (22) |
Date of filing: 03.12.2007 |
|
| (51) |
International Patent Classification (IPC):
|
| (86) |
International application number: |
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PCT/JP2007/073336 |
| (87) |
International publication number: |
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WO 2008/081673 (10.07.2008 Gazette 2008/28) |
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| (84) |
Designated Contracting States: |
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AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO
SE SI SK TR |
| (30) |
Priority: |
28.12.2006 JP 2006356310
28.12.2006 JP 2006356312
|
| (71) |
Applicant: Kabushiki Kaisha Kobe Seiko Sho |
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Chuo-ku
Kobe-shi
Hyogo 651-8585 (JP) |
|
| (72) |
Inventors: |
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- SUGIMURA, Tomoko
c/o Kobe Corporate Research Laboratories
in Kobe Steel, Ltd.,
Kobe-shi, Hyogo 651-2271 (JP)
- SAKAMOTO, Koichi
c/o Kobe Corporate Research Laboratories
in Kobe Steel, Ltd.,
Kobe-shi, Hyogo 651-2271 (JP)
|
| (74) |
Representative: Müller-Boré & Partner
Patentanwälte |
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Grafinger Strasse 2
81671 München
81671 München (DE) |
|
| |
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| (54) |
Si KILLED STEEL WIRE MATERIAL HAVING EXCELLENT FATIGUE PROPERTY AND SPRING |
(57) A Si-killed steel wire rod for obtaining a spring excellent in fatigue properties
and a spring excellent in fatigue properties obtained from the steel wire rod are
provided.
The Si-killed steel wire rod of the present invention contains Sr: 0.03-20 ppm (means
"mass ppm", hereinafter the same), Al: 1-30 ppm and Si: 0.2-4% (means "mass%", hereinafter
the same) respectively, and contains Mg and/or Ca by a range of 0.5-30 ppm in total.
Also, in the Si-killed steel wire rod of the present invention, oxide-based inclusions
present in the wire rod contain SiO
2: 30-90%, Al
2O
3: 2-50%, MgO: 35% or below (not inclusive of 0%), CaO: 50% or below (not inclusive
of 0%), MnO: 20% or below (not inclusive of 0%) and SrO: 0.2-15% respectively, and
total content of (CaO+MgO) is 3% or above.
A spring excellent in fatigue properties can be obtained by forming the spring from
such steel wire rod.