HIGH-STRENGTH PC STEEL WIRE - NIPPON STEEL & SUMITOMO METAL CORP

Title:

HIGH-STRENGTH PC STEEL WIRE

Document Type and Number:

WIPO Patent Application WO/2017/014232

Kind Code:

A1

Abstract:

The chemical composition of this high-strength PC steel wire comprises, in mass%, C: 0.90-1.10%, Si: 0.80-1.50%, Mn: 0.30-0.70%, P: 0.030% or less, S: 0.030% or less, Al: 0.010-0.070%, N: 0.0010-0.010%, Cr: 0-0.50%, V: 0-0.10%, B: 0-0.005%, Ni: 0-1.0%, Cu: 0-0.50%, and the remainder is Fe and impurities. The ratio of the Vickers hardness (HvS) of the area 0.1D [D: diameter of steel wire] from the surface of the steel wire (the surface layer) and the Vickers hardness (HvI) of the area interior to the surface layer satisfies [1.10 < HvS/HvI ≦ 1.15]. The average carbon concentration of the region from the surface of the steel wire up to 10μm deep (the outermost layer) is no more than 0.8 times the carbon concentration of the steel wire. The metal structure in the region interior to the aforementioned outermost layer region is, by area%, a pearlite structure: greater than or equal to 95%, and has a tensile strength of 2000-2400 MPa. This high-strength PC steel wire has a simple manufacturing method and has excellent delayed fracture resistance.

Inventors:

OKONOGI MAKOTO (JP)
HIRAKAMI DAISUKE (JP)
YAMADA MASATO (JP)
OSHIMA KATSUHITO (JP)
TANAKA SHUICHI (JP)

Application Number:

PCT/JP2016/071265

Publication Date:

January 26, 2017

Filing Date:

July 20, 2016

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)
SUMITOMO (SEI) STEEL WIRE CORP (JP)

International Classes:

C22C38/00; C21D8/08; C22C38/54

Domestic Patent References:

WO2011089782A1

2011-07-28

Foreign References:

JP2014136823A	2014-07-28
JP2014136822A	2014-07-28
JP2009280836A	2009-12-03
JP2003129177A	2003-05-08
JP2007039799A	2007-02-15
JPH07268546A	1995-10-17

Other References: