US 12,305,287 B2
Plated steel sheet having excellent strength, formability and surface property and method for manufacturing same
Yong-Hoon Choi, Gwangyang-si (KR); Yu-Mi Ha, Gwangyang-si (KR); Seong-Ho Han, Gwangyang-si (KR); and Jun-Sung Yeom, Gwangyang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Appl. No. 18/266,267
Filed by POSCO CO., LTD, Pohang-si (KR)
PCT Filed Dec. 2, 2021, PCT No. PCT/KR2021/018102
§ 371(c)(1), (2) Date Jun. 8, 2023,
PCT Pub. No. WO2022/131635, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 10-2020-0175088 (KR), filed on Dec. 15, 2020.
Prior Publication US 2024/0043952 A1, Feb. 8, 2024
Int. Cl. C23C 2/28 (2006.01); B32B 15/01 (2006.01); C21D 1/84 (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 38/06 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C23C 2/06 (2006.01); C23C 2/26 (2006.01)
CPC C23C 2/28 (2013.01) [B32B 15/013 (2013.01); C21D 1/84 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/0205 (2013.01); C21D 8/021 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 8/0263 (2013.01); C21D 8/0278 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/004 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C23C 2/06 (2013.01); C23C 2/26 (2013.01); C21D 2211/005 (2013.01); C21D 2211/009 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A plated steel sheet comprising:
a base iron; and
a plating layer formed on the base iron,
wherein the base iron includes, by weight, C: 0.003 to 0.009%, Si: 0.05% or less (excluding 0%), Mn: 0.4 to 1.0% (excluding 0%), P: 0.04 to 0.09%, S: 0.01% or less (excluding 0%), N: 0.005% or less (excluding 0%), Sol.Al: 0.1% or less (excluding 0%), Mo: 0.03 to 0.08%, Ti: 0.005 to 0.03%, Nb: 0.02 to 0.045%, Cu: 0.04 to 0.15%, B: 0.0015% or less (excluding 0%), and a balance of Fe and other unavoidable impurities,
wherein the plated steel sheet satisfies the following relationships 1 and 2:
0<10×[Si]/[Mn]≤1.3  [Relationship 1]
in relationship 1, [Si] represents an average weight % amount of Si in the base iron, and [Mn] represents an average weight % amount of Mn in the base iron; and
0≤[Ao]/[At]≤0.15  [Relationship 2]
in relationship 2, [At] represents an area of a region between an interface line and a spaced line, and [Ao] represents an area occupied by an Mn—Si—O-based composite oxide in the region, wherein the interface line is defined by a line having a length of 500 nm or more between the base iron and the plating layer on a cross-section of the plated steel sheet, and the spaced line is defined by a line spaced apart by 0.3 μm from the interface line in a thickness direction facing the plating layer on the cross-section of the plated steel sheet.