Title:
HIGH-STRENGTH SPRING STEEL WIRE, HIGH-STRENGTH SPRINGS AND PROCESSES FOR PRODUCTION OF BOTH
Document Type and Number:
WIPO Patent Application WO/2008/102573
Kind Code:
A1
Abstract:
The invention provides a high-strength spring excellent in corrosion fatigue characteristics;
a steel wire for high -strength springs; and processes for the production of both.
A steel wire for high-strength springs which contains by mass C: 0.35 to 0.50%,
Si: 1.00 to 3.00%, Mn: 0.10 to 2.00%, P: 0.015% or below, and S: 0.015% or below with
the balance consisting of Fe and unavoidable impurities, characterized in that
in the differential scanning calorimetry accompanied with heating from 50°C
to 600°C at a temperature rise rate of 0.25°C/s, an exothermic reaction
peak is present only at 450°C or above; high-strength springs; and a process
for the production of high-strength springs, characterized by conducting tempering
under the conditions satisfying the following relationship (wherein T[K] is
tempering temperature; t[s] is tempering time; and Si%[mass%] is content of
Si): 16000 < (T-40Œ[Si%]) Œ (31.7+log t) <
23000
Inventors:
KUBOTA MANABU (JP)
HASHIMURA MASAYUKI (JP)
HASHIMURA MASAYUKI (JP)
Application Number:
PCT/JP2008/050226
Publication Date:
August 28, 2008
Filing Date:
January 07, 2008
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
KUBOTA MANABU (JP)
HASHIMURA MASAYUKI (JP)
KUBOTA MANABU (JP)
HASHIMURA MASAYUKI (JP)
International Classes:
C22C38/00; C21D9/02; C21D9/52; C22C38/04; C22C38/60; F16F1/02
Foreign References:
JP2006291291A | 2006-10-26 | |||
JPH09324219A | 1997-12-16 | |||
JP2004143482A | 2004-05-20 | |||
JP2002356747A | 2002-12-13 |
Other References:
See also references of EP 2058414A4
Attorney, Agent or Firm:
AOKI, Atsushi et al. (Toranomon 37 Mori Bldg.5-1, Toranomon 3-chome,Minato-k, Tokyo 23, JP)
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