SPRING AND METHOD FOR PRODUCING SAME

Title:

SPRING AND METHOD FOR PRODUCING SAME

Document Type and Number:

WIPO Patent Application WO/2011/129179

Kind Code:

A1

Abstract:

A spring characterized by: having a total composition comprising, in terms of wt%, 0.27-0.48% of C, 0.01-2.2% of Si, 0.30-1.0% of Mn, not more than 0.035% of P, and not more than 0.035% of S, the balance being Fe and inevitable impurities; the thicknesses of a nitrogen compound layer and carbon compound layer on the surface being not more than 2 μm; the hardness at the center part of the cross section being 500-700 HV; a compressive residual stress layer with a thickness of 0.30 mm to D/4 [wherein D stands for the circle equivalent diameter (mm) of the cross section] being formed in the surface layer; and the maximum compression residual stress thereof being 1400-2000 MPa.

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Inventors:

SUZUKI TAKESHI (JP)
ONO YOSHIKI (JP)
KUROKAWA SHIMPEI (JP)

Application Number:

PCT/JP2011/056923

Publication Date:

October 20, 2011

Filing Date:

March 23, 2011

Export Citation:

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Assignee:

NHK SPRING CO LTD (JP)
SUZUKI TAKESHI (JP)
ONO YOSHIKI (JP)
KUROKAWA SHIMPEI (JP)

International Classes:

C22C38/00; C21D1/06; C21D7/06; C21D9/02; C22C38/04; C23C8/32

Foreign References:

JPS58193323A	1983-11-11
JPS62137133A	1987-06-20
JPH11241143A	1999-09-07
JP2009052144A	2009-03-12
JPH0328438B2	1991-04-19
JP2005139508A	2005-06-02
JPH06158226A	1994-06-07
JP2003170353A	2003-06-17
JP2007046088A	2007-02-22

Other References: