US 12,247,358 B2
Rail
Masaharu Ueda, Tokyo (JP); Teruhisa Miyazaki, Tokyo (JP); Takuya Tanahashi, Tokyo (JP); and Yusuke Maeda, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/432,607
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Mar. 2, 2020, PCT No. PCT/JP2020/008606
§ 371(c)(1), (2) Date Aug. 20, 2021,
PCT Pub. No. WO2020/189232, PCT Pub. Date Sep. 24, 2020.
Claims priority of application No. 2019-048809 (JP), filed on Mar. 15, 2019.
Prior Publication US 2022/0120039 A1, Apr. 21, 2022
Int. Cl. E01B 5/08 (2006.01); C21D 6/00 (2006.01); C21D 8/00 (2006.01); C21D 9/04 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/10 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/18 (2006.01)
CPC E01B 5/08 (2013.01) [C21D 6/001 (2013.01); C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/007 (2013.01); C21D 6/008 (2013.01); C21D 8/005 (2013.01); C21D 9/04 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/10 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/18 (2013.01); C21D 2211/009 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A rail comprising steel composition including, by mass %:
C: 0.75 to 1.20%;
Si: 0.10 to 2.00%;
Mn: 0.10 to 2.00%;
Cr: 0 to 2.00%;
Mo: 0 to 0.50%;
Co: 0 to 1.00%;
B: 0 to 0.0050%;
Cu: 0 to 1.00%;
Ni: 0 to 1.00%;
V: 0 to 0.50%;
Nb: 0 to 0.050%;
Ti: 0 to 0.0500%;
Mg: 0 to 0.0200%;
Ca: 0 to 0.0200%;
REM: 0 to 0.0500%;
Zr: 0 to 0.0200%;
N: 0 to 0.0200%;
Al: 0 to 1.00%;
P: 0.0250% or less;
S: 0.0250% or less; and
a remainder including Fe and impurities,
wherein 90 area % or greater of a metallographic structure in a cross section of a rail web portion is a pearlite structure,
a minimum value of a hardness in the cross section of the rail web portion is Hv 300 or greater, and
a difference between a maximum value and the minimum value of the hardness in the cross section of the rail web portion is Hv 40 or less.