STEEL WIRE FOR SPRINGS, AND SPRING - NIPPON STEEL & SUMITOMO METAL CORP

Title:

STEEL WIRE FOR SPRINGS, AND SPRING

Document Type and Number:

WIPO Patent Application WO/2017/039012

Kind Code:

A1

Abstract:

A steel wire for springs contains C: 0.40-0.75% by mass, Si: 1.00-5.00% by mass, Mn: 0.20-2.00% by mass, P: 0.0001-0.0500% by mass, S: 0.0001-0.0500% by mass, Cr: 0.50-3.50% by mass, Al: 0.0005-0.0500% by mass, N: 0.0020-0.0100%% by mass, Mo: 0-2.00% by mass, V: 0-0.50% by mass, W: 0-0.50% by mass, Nb: 0-0.100% by mass, Ti: 0-0.100% by mass, Ca: 0-0.0100% by mass, Mg: 0-0.0100% by mass, Zr: 0-0.1000% by mass, B: 0-0.0100% by mass, Cu: 0-1.00% by mass, and Ni: 0-3.00% by mass, the remainder being Fe and inevitable impurities. The structure includes tempered martensite having an area ratio of 90% or greater. The old austenite grain size number is 12.5 or higher. The concentration of iron carbide having an equivalent circle diameter of 0.15-0.50 μm is 0.40 units/μm2 to 2.00 units/μm2 inclusive.

Inventors:

TERAMOTO SHINYA (JP)
YARITA HIROSHI (JP)
SUZUKI SHOUICHI (JP)

Application Number:

PCT/JP2016/075961

Publication Date:

March 09, 2017

Filing Date:

September 05, 2016

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)
NIPPON STEEL & SUMIKIN SG WIRE CO LTD (JP)

International Classes:

C22C38/00; C22C38/60; F16F1/02; C21D9/52

Domestic Patent References:

WO2011004913A1

2011-01-13

Foreign References:

JP2004143482A	2004-05-20
JP2011214118A	2011-10-27
JP2005220392A	2005-08-18

Other References: