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Patent Searching and Data


Title:
ROLLED STEEL MATERIAL FOR HIGH-STRENGTH SPRING AND WIRE FOR HIGH-STRENGTH SPRING USING SAME
Document Type and Number:
WIPO Patent Application WO/2015/098531
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a rolled steel material which is for use in a high-strength spring, which exhibits excellent wire drawability even when the amount of an alloying element added is reduced, and which exhibits excellent corrosion fatigue characteristics after quenching and tempering. A rolled steel material for a high-strength spring, characterized in that: the rolled steel contains C, Si, Mn, P, S, Al, Cu and Ni; the nondiffusible hydrogen content is 0.40massppm or less; the area fraction of ferrite in terms of percentage satisfies relationship (1); and the total area fraction of bainite and martensite is 2% or less. Area fraction of ferrite < {(0.77 - [C])/0.77 - [C]/3 + 0.08} × 100 ... (1) [wherein "[element]" represents the content of the element in terms of mass%]

Inventors:
TAKEDA ATSUHIKO
MASUDA TOMOKAZU
TAKAYAMA SHO
Application Number:
PCT/JP2014/082728
Publication Date:
July 02, 2015
Filing Date:
December 10, 2014
Export Citation:
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Assignee:
KOBE STEEL LTD (JP)
International Classes:
C22C38/00; B21C1/00; C21D3/06; C21D8/06; C21D9/52; C22C38/16; C22C38/54
Foreign References:
JP2011184705A2011-09-22
JP2009024245A2009-02-05
JP2007327084A2007-12-20
JP2006241528A2006-09-14
JP2005029870A2005-02-03
JP2005023404A2005-01-27
JP2002115023A2002-04-19
JP2004143482A2004-05-20
JP2006183137A2006-07-13
JP2007231347A2007-09-13
Other References:
See also references of EP 3088551A4
Attorney, Agent or Firm:
UEKI, Kyuichi et al. (JP)
Hisakazu Ueki (JP)
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