	US 12,227,824 B2
	Steel wire rod enabling omission of softening heat treatment and method of manufacturing same
Jae-Seung Lee, Pohang-si (KR); Yo-Sep Yang, Pohang-si (KR); In-Gyu Park, Pohang-si (KR); and Han-Hwi Kim, Pohang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Appl. No. 17/288,998
Filed by POSCO, Pohang-si (KR)
PCT Filed Oct. 18, 2019, PCT No. PCT/KR2019/013702 § 371(c)(1), (2) Date Apr. 27, 2021, PCT Pub. No. WO2020/091277, PCT Pub. Date May 7, 2020.
Claims priority of application No. 10-2018-0132073 (KR), filed on Oct. 31, 2018.
Prior Publication US 2021/0404039 A1, Dec. 30, 2021
Int. Cl. C22C 38/22 (2006.01); C21D 8/00 (2006.01); C21D 8/06 (2006.01); C21D 9/52 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01)

CPC C22C 38/22 (2013.01) [C21D 8/065 (2013.01); C21D 9/525 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C21D 2211/005 (2013.01); C21D 2211/009 (2013.01)]

7 Claims

1. A steel wire rod enabling omission of softening heat treatment, the steel wire rod comprising:

by weight %, 0.2-0.45% of C, 0.02-0.4% of Si, 0.3-1.5% of Mn, 0.01-1.5% of Cr, 0.02-0.05% of Al, 0.01-0.5% of Mo, 0.01% or less of N, and a balance Fe and other inevitable impurities,

wherein a microstructure has a main phase of a composite structure of proeutectoid ferrite+pearlite, and includes 10 area % or less of one or more of bainite or martensite, and

wherein an average colony size of pearlite is 5 μm or less.