SHAFT COMPONENT - NIPPON STEEL & SUMITOMO METAL CORP

Title:

SHAFT COMPONENT

Document Type and Number:

WIPO Patent Application WO/2018/056332

Kind Code:

A1

Abstract:

Provided is a shaft component exhibiting excellent static torsional strength and torsional fatigue strength. Thus, a shaft component having a chemical composition satisfying formula (1) and containing as essential elements, in mass%, C in the amount of 0.35-0.70%, Si in the amount of 0.01-0.40%, Mn in the amount of 0.5-2.6%, P in the amount of 0.050% or less, S in the amount of 0.005-0.020%, Al in the amount of 0.010-0.050%, N in the amount of 0.005-0.025%, and O in the amount of 0.003% or less, and also containing optionally selected elements, with Fe and impurities constituting the remainder thereof, wherein: one or more holes are present in the outer-circumferential surface thereof; the volume (R1) by percentage of retained austenite at a depth of 2mm from the outer-circumferential surface is 4-20%; and given that the volume by percentage of retained austenite at a depth of 2mm from the outer-circumferential surface in the axial direction of the holes and a depth of 20μm from the surface of the holes is R2, the reduction rate Δγ of retained austenite obtained by formula (A): Δγ=[(R1-R2)/R1] ×100 is 40% or more. Formula (1): 15.0≤25.9C+6.35Mn+2.88Cr+3.09Mo+2.73Ni≤27.2 (The notation for each element in the formula represents the content of said element).

Inventors:

IWASAKI TATSUYA (JP)
WATARI KOJI (JP)
SUENO HIDEKAZU (JP)

Application Number:

PCT/JP2017/033984

Publication Date:

March 29, 2018

Filing Date:

September 20, 2017

Export Citation:

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Assignee:

NIPPON STEEL & SUMITOMO METAL CORP (JP)

International Classes:

C21D9/28; C21D1/10; C22C38/00; C22C38/06; C22C38/60; F16C3/02

Domestic Patent References:

WO2017026307A1

2017-02-16

Foreign References:

JP2009197314A	2009-09-03
JP2004027334A	2004-01-29
JP2006342904A	2006-12-21
JP2017082299A	2017-05-18

Other References: