US 11,952,649 B2
High-strength stainless steel
Jong Jin Jeon, Pohang-si (KR); Mi-Nam Park, Pohang-si (KR); and Sang Seok Kim, Pohang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Appl. No. 17/312,119
Filed by POSCO, Pohang-si (KR)
PCT Filed Aug. 23, 2019, PCT No. PCT/KR2019/010786
§ 371(c)(1), (2) Date Jun. 9, 2021,
PCT Pub. No. WO2020/130279, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 10-2018-0164564 (KR), filed on Dec. 18, 2018.
Prior Publication US 2022/0033941 A1, Feb. 3, 2022
Int. Cl. C22C 38/44 (2006.01); C21D 6/00 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/42 (2006.01)
CPC C22C 38/44 (2013.01) [C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0263 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/42 (2013.01); C21D 2211/001 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A high strength stainless steel comprising, in percent (%) by weight of the entire composition, C: 0.14 to 0.20%, Si: 0.8 to 1.0%, Mn: more than 0 and 0.5% or less, Cr: 15.0 to 17.0%, Ni: 4.0 to 5.0%, Mo: 0.6 to 0.8%, Cu: 0.5% or less, N: 0.05 to 0.11%, the remainder of iron (Fe) and other inevitable impurities, and
C+N: 0.25% or more and Md30 value represented by a following Equation (1) satisfies 40° C. or more.
Md30(° C.)=551−462*(C+N)−9.2*Si−8.1*Mn−13.7*Cr−29*(Ni+Cu)−18.5*Mo  (1)
(Here, C, N, Si, Mn, Cr, Ni, Cu, Mo mean the content (% by weight) of each element)