US 12,270,108 B2
Plated steel sheet having excellent corrosion resistance, workability and surface quality and method for manufacturing same
Il-Ryoung Sohn, Gwangyang-si (KR); Sung-Joo Kim, Pohang-si (KR); Tae-Chul Kim, Gwangyang-si (KR); Bong-Hwan Yoo, Gwangyang-si (KR); Myung-Soo Kim, Pohang-si (KR); Jong-Sang Kim, Gwangyang-si (KR); Sang-Tae Han, Pohang-si (KR); and Kwang-Won Kim, Pohang-si (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Appl. No. 18/010,868
Filed by POSCO, Gyeongsangbuk-do (KR)
PCT Filed Jun. 18, 2021, PCT No. PCT/KR2021/007705
§ 371(c)(1), (2) Date Dec. 16, 2022,
PCT Pub. No. WO2021/256906, PCT Pub. Date Dec. 23, 2021.
Claims priority of application No. 10-2020-0075335 (KR), filed on Jun. 19, 2020.
Prior Publication US 2023/0235438 A1, Jul. 27, 2023
Int. Cl. C23C 2/06 (2006.01); C21D 8/02 (2006.01); C22C 18/00 (2006.01); C22C 18/04 (2006.01); C23C 2/00 (2006.01); C23C 2/02 (2006.01); C23C 2/40 (2006.01)
CPC C23C 2/06 (2013.01) [C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C22C 18/00 (2013.01); C22C 18/04 (2013.01); C23C 2/0035 (2022.08); C23C 2/02 (2013.01); C23C 2/40 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A plated steel sheet, comprising:
a base steel sheet;
a Zn—Mg—Al based steel sheet plating layer provided on at least one surface of the base steel sheet; and
an Fe—Al based inhibition layer provided between the base steel sheet and the Zn—Mg—Al based plating layer,
wherein the plating layer comprises, by weight:
4% or more of Mg; 2.1 times or more of a Mg content and 14.2% or less of Al; 0.2% or less (including 0%) of Si; 0.1% or less (including 0%) of Sn, with a balance of Zn and unavoidable impurities,
wherein, in a cut surface of the steel sheet in a thickness direction, when an interface line of the base steel sheet is spaced 5 μm apart toward a surface of the plating layer, a length occupied by an outburst phase intersecting the spaced line is 10% or less compared to a length of the spaced line, and,
a Fe content of the outburst phase is 10 to 45% by weight, and an alloy phase of the outburst phase contains at least one of Fe2Al5, FeAl and Fe—Zn compounds, and contains 20% or more of Zn by weight, and
wherein the outburst phase is an alloy phase including a Fe—Al based intermetallic compound other than the inhibition layer.