STEEL WIRE FOR BEARING WITH EXCELLENT WIRE DRAWABILITY AND COIL FORMABILITY AFTER WIREDRAWING

Title:

STEEL WIRE FOR BEARING WITH EXCELLENT WIRE DRAWABILITY AND COIL FORMABILITY AFTER WIREDRAWING

Document Type and Number:

WIPO Patent Application WO/2016/063867

Kind Code:

A1

Abstract:

This steel wire contains, in terms of mass%, 0.95-1.10% C, 0.10-0.70% Si, 0.20-1.20% Mn, 0.90-1.60% Cr, 0-0.25% Mo, 0-25 ppm B, 0-0.020% P, 0-0.020% S, 0-0.0010% O, 0-0.030% N, and 0.010-0.100% Al. In the steel wire, the surface layer region has a Vickers hardness of HV300-HV420, an areal pearlite proportion of 80% or greater, and an areal pro-eutectoid cementite proportion of 2.0% or less, and the areal proportion of pearlite blocks having an equivalent circular diameter exceeding 40 µm in the surface layer region is 0.62% or less. In the steel wire, the inner part region has an areal pearlite proportion of 90% or greater and an areal pro-eutectoid cementite proportion of 5.0% or less. The difference in Vickers hardness between the surface layer region and the center part is HV20.0 or less.

Inventors:

SAKAMOTO MASASHI (JP)
KODAMA JUNICHI (JP)
NAKAMURA KENICHI (JP)

Application Number:

PCT/JP2015/079550

Publication Date:

April 28, 2016

Filing Date:

October 20, 2015

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

C22C38/00; C22C38/32; B21B1/16; B21B3/00; C21D8/06

Foreign References:

JP2012233254A	2012-11-29
JP2008007856A	2008-01-17
JP2005281860A	2005-10-13
JP2000337334A	2000-12-05

Other References: