US 12,486,549 B2
Moderate-strength steel rail and production method thereof
Jun Yuan, Panzhihua (CN); Yong Deng, Panzhihua (CN); Chongmu Chen, Panzhihua (CN); and Yuan Wang, Panzhihua (CN)
Assigned to PANGANG GROUP PANZHIHUA IRON & STEEL RESEARCH INSTITUTE CO., LTD., Panzhihua (CN)
Appl. No. 17/996,603
Filed by PANGANG GROUP PANZHIHUA IRON & STEEL RESEARCH INSTITUTE CO., LTD., Panzhihua (CN)
PCT Filed Jun. 30, 2022, PCT No. PCT/CN2022/102696
§ 371(c)(1), (2) Date Oct. 19, 2022,
PCT Pub. No. WO2023/077838, PCT Pub. Date May 11, 2023.
Claims priority of application No. 202111292347.4 (CN), filed on Nov. 3, 2021.
Prior Publication US 2024/0068063 A1, Feb. 29, 2024
Int. Cl. C21D 9/04 (2006.01); B21B 1/085 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C21D 8/00 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/18 (2006.01); E01B 5/02 (2006.01)
CPC C21D 9/04 (2013.01) [B21B 1/085 (2013.01); C21D 1/18 (2013.01); C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/005 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/18 (2013.01); E01B 5/02 (2013.01); C21D 2221/00 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A production method for a steel rail, comprising:
smelting and casting steel to form steel billet, wherein the steel has the following chemical compositions in weight percentages: carbon 0.70-0.90 wt %, silicon 0.08-0.65 wt %, manganese 0.69-1.31 wt %, chromium 0.10-0.25 wt %, phosphorus ≤0.020 wt %, sulfur ≤0.020 wt %, and iron 96.85-98.41 wt %;
heating and rolling the steel billet into the steel rail;
performing heat treatment on the steel rail by using rolling residual heat; and
applying accelerated cooling to a whole section of the steel rail after the heat treatment;
wherein the steel billet is heated at a temperature of 1200-1250° C. and maintained at a holding time of 150-240 min in a soaking segment;
wherein temperature of the rolling residual heat is 620-780° C. while the heat treatment is performed; and
wherein a cooling rate of 1-4° C./s is applied to a width of 50-60 mm of a rail head tread of the steel rail while the heat treatment is performed.