US 12,000,028 B2
Rail vehicle axle
Taizo Makino, Kobe (JP); Takayuki Kamimura, Takarazuka (JP); Yuichiro Yamamoto, Amagasaki (JP); Yutaka Wakasu, Boalsburg, PA (US); Kiyonobu Sugae, Nishinomiya (JP); Yukiteru Takeshita, Nishinomiya (JP); and Naomitsu Mizui, Amagasaki (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 15/751,020
Filed by NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo (JP)
PCT Filed Aug. 17, 2016, PCT No. PCT/JP2016/074038
§ 371(c)(1), (2) Date Feb. 7, 2018,
PCT Pub. No. WO2017/033818, PCT Pub. Date Mar. 2, 2017.
Claims priority of application No. 2015-165162 (JP), filed on Aug. 24, 2015.
Prior Publication US 2018/0245189 A1, Aug. 30, 2018
Int. Cl. C22C 38/50 (2006.01); B61F 5/50 (2006.01); C21D 1/28 (2006.01); C21D 6/00 (2006.01); C21D 8/06 (2006.01); C21D 9/08 (2006.01); C21D 9/28 (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 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/18 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); F16C 3/02 (2006.01)
CPC C22C 38/50 (2013.01) [B61F 5/50 (2013.01); C21D 1/28 (2013.01); C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/065 (2013.01); C21D 9/08 (2013.01); C21D 9/28 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/18 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); F16C 3/02 (2013.01); F16C 2204/62 (2013.01); F16C 2326/10 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A rail vehicle axle comprising:
a chemical composition consisting of, in mass %,
C: 0.20 to 0.35%,
Si: 0.20 to 0.65%,
Mn: 0.40 to 1.20%,
P: 0.020% or less,
S: 0.020% or less,
Sn: 0.21 to 0.40%,
N: 0.0200% or less,
Cu: 0 to 0.30%,
Ni: 0 to 0.30%,
Al: 0 to 0.100%,
V: 0 to 0.060%, and
one or more from the group consisting of Cr: more than 0.20 to 0.30%, Mo: 0.005 to 0.08%, and Ti: 0.002 to 0.020%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2):
0.58≤C+Si/8+Mn/5+Cu/10+Cr/4+V≤0.67  (1)
Si+0.9Cr≥0.60  (2)
where each element symbol in Formulae (1) and (2) is substituted by the content (mass %) of a corresponding element,
wherein the smooth fatigue limit is more than 270 MPa,
the notched fatigue limit is more than 195 MPa, and
a notch factor of the rail vehicle axle is not more than 1.47, where notch factor is defined by smooth fatigue limit divided by notched fatigue limit.