RAILROAD WHEEL

WIPO Patent Application WO/2022/220237

A1

Provided is a railroad wheel having excellent toughness at a boss portion. A railroad wheel according to the present disclosure comprises a rim portion, a boss portion having a through-hole, and a plate portion. The railroad wheel has a chemical composition comprising, by mass%, 0.60 to 0.80% of C, 1.00% or less of Si, 0.10 to 1.50% of Mn, 0.050% or less of P, 0.030% or less of S, 0.0200% or less of N, and the balance Fe and impurities. In a cross-section of the boss portion when the boss portion is cut in a central axis direction of the through-hole along a plane including the central axis, wherein 15 mm x 15 mm regions defined by multiple axial line segments, which are parallel to the central axis and arranged at a pitch of 15 mm in a radial direction of the railroad wheel from an inner peripheral surface of the through-hole, and multiple radial line segments, which are perpendicular to the central axis and arranged at a pitch of 15 mm in the central axis direction from a surface of the boss portion where the opening of the through-hole is formed, are defined as rectangular regions, each of the rectangular regions in the cross-section of the boss portion has an average C concentration of less than 0.90 mass%.

MAEJIMA TAKETO (JP)
OSAKA TARO (JP)
YAMAMOTO YUICHIRO (JP)
MATSUI NAOKI (JP)

PCT/JP2022/017582

October 20, 2022

April 12, 2022

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NIPPON STEEL CORP (JP)

B60B17/00; C22C38/00; C22C38/50; C21D8/00; C21D9/34

WO2015190088A1	2015-12-17
WO2015190088A1	2015-12-17

JPS57143465A	1982-09-04
JPH09202937A	1997-08-05
JP2012107295A	2012-06-07
JPH07308730A	1995-11-28
JPH09202937A	1997-08-05
JP2000345295A	2000-12-12
JP2012107295A	2012-06-07

ASCEND IP LAW FIRM (JP)

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