| (19) |
 |
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(11) |
EP 2 034 036 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
06.10.2010 Bulletin 2010/40 |
| (43) |
Date of publication A2: |
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11.03.2009 Bulletin 2009/11 |
| (22) |
Date of filing: 08.08.2008 |
|
| (51) |
International Patent Classification (IPC):
|
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL
PT RO SE SI SK TR |
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Designated Extension States: |
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AL BA MK RS |
| (30) |
Priority: |
05.09.2007 JP 2007230713
|
| (71) |
Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) |
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Kobe-shi,
Hyogo 651-8585 (JP) |
|
| (72) |
Inventors: |
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- Kochi, Takuya
Kobe-shi
Hyogo 651-2271 (JP)
- Maruo, Tomotada
Kobe-shi
Hyogo 657-0863 (JP)
- Nishimura, Masumi
Kagogawa-shi
Hyogo 675-0137 (JP)
|
| (74) |
Representative: Müller-Boré & Partner
Patentanwälte |
|
Grafinger Straße 2
81671 München
81671 München (DE) |
|
| |
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| (54) |
Wire rod having excellent wire drawability and its production method |
(57) A wire rod, whose tensile strength after wire drawing becomes more or less 3,000
MPa, which does not cause wire breakage even if wire drawing speed is increased, which
does not shorten the life time of a dice, and whose wire drawability is improved,
contains C: 0.65-0.75%, Si: 0.1-0.5%, Mn: 0.1-0.6%, P: 0.015% or below (not including
0%), S: 0.015% or below (not including 0%), N: 0.004% or below (not including 0%),
Al: 0.003% or below (not including 0%), O: 0.003% or below (not including 0%), the
balance being iron and inevitable impurities, tensile strength (TS) being 960 MPa
or below, and reduction of area (RA) being 40% or above.