公开(公告)号：US12221701B2

公开(公告)日：2025-02-11

申请号：US18622583

申请日：2024-03-29

Applicant: POSCO CO., LTD

Inventor： Ki-Cheol Kang ,  Sang-Ho Uhm ,  Chang-Woon Jee ,  Yeon-Chae Jeong ,  Kwang-Tai Min

IPC: C23C2/06 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/28 ,  C23C2/40

Abstract: A welded member includes: a first steel sheet including a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet; and a second steel sheet spot-welded on the first steel sheet and facing the zinc-based plating layer of the first steel sheet, a spot-welded zone being formed between the first steel sheet and the second steel sheet. A surface layer of the base steel sheet has a decarburization ratio of 30% or more. The decarburization ratio is represented by equation: Decarburization ratio (%) of surface layer=(1−average carbon concentration in surface layer/bulk carbon concentration)*100 where the surface layer refers to a region of the base steel sheet from the surface thereof to a depth of 35 μm. A shoulder portion of the spot-welded zone includes a B-type crack having a length of 100 μm or less, and no C-type crack.

公开(公告)号：US11981973B2

公开(公告)日：2024-05-14

申请号：US17779923

申请日：2020-12-03

Applicant: POSCO

Inventor： Ki-Cheol Kang ,  Chung-Hwan Lee

IPC: B32B15/01 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/06 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/022 ,  C23C2/024 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  B32B2307/718

Abstract: The present disclosure relates to a zinc plated steel sheet having excellent fatigue strength of electrical resistance spot welds and a method for manufacturing the same. According to an aspect of the present disclosure, a zinc plated steel sheet includes a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet, wherein a concentration profile of one or two of oxygen, and silicon and manganese measured in a depth direction from the surface of the base steel sheet has a maximum point in the depth direction from the surface, and an absolute value of a difference between a depth at which the maximum point of the concentration profile of oxygen is formed and a depth at which the maximum point of the concentration profile of one of silicon and manganese is formed is 0.5 μm or less.

公开(公告)号：US10344361B2

公开(公告)日：2019-07-09

申请号：US15534295

申请日：2015-12-08

Applicant: POSCO

Inventor： Myung-Soo Kim ,  Ki-Cheol Kang

IPC: C22C38/02 ,  C22C38/06 ,  C22C38/04 ,  C22C38/60 ,  C21D8/02 ,  C23C2/06 ,  B32B15/00 ,  B32B15/01 ,  B32B15/04 ,  B32B15/18 ,  C23C28/02 ,  C23C30/00 ,  C23C2/12 ,  C23C28/00 ,  C21D6/00 ,  C23C2/02 ,  C23C2/28 ,  C23C2/40 ,  C22C38/00 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C21D8/04 ,  C21D9/48 ,  C21D9/56

Abstract: The present invention relates to an ultra-high strength, hot-dip galvanized steel sheet having excellent surface quality and coating adherence and to a method for manufacturing thereof, the ultra-high strength, hot-dip galvanized steel sheet comprising: 0.1-0.3% by weight carbon (C); 0.1-2.0% by weight silicon (Si); 0.005-1.5% by weight aluminum (Al); 1.5-3.5% by weight manganese (Mn); 0.04% by weight or less phosphorus (P) (excluding 0% by weight); 0.015% by weight or less sulphur (S) (excluding 0% by weight); 0.02% by weight or less nitrogen (N) (excluding 0% by weight); the balance being Fe; and other inevitable impurities, and further comprising 0.01 wt.% to 0.07 wt.% of at least one kind of element selected from the group consisting of bismuth (Bi), tin (Sn) and antimony (Sb).

公开(公告)号：US20240043953A1

公开(公告)日：2024-02-08

申请号：US18267029

申请日：2021-12-17

Applicant: POSCO Co., Ltd

Inventor： Ki-Cheol Kang ,  Tae-Chul Kim ,  Myung-Soo Kim ,  Jong-Sang Kim

IPC: C21D9/46 ,  C22C38/38 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/60 ,  C22C38/26 ,  C22C38/22 ,  C22C38/14 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D1/74 ,  C21D1/18 ,  C21D6/00 ,  B32B15/01 ,  C23C2/28 ,  C23C2/06

CPC classification number: C21D9/46 ,  C22C38/38 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/60 ,  C22C38/26 ,  C22C38/22 ,  C22C38/14 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/008 ,  C22C38/002 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C21D8/0278 ,  C21D1/74 ,  C21D1/18 ,  C21D8/0294 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  B32B15/013 ,  C23C2/28 ,  C23C2/06 ,  C21D2221/02

Abstract: A hot-dip galvanized steel sheet according to one aspect of the present invention comprises a base steel sheet and a hot-dip galvanized layer formed on the surface of the base steel sheet, wherein the difference between the average of the Mn/Si values of surface oxides present on a surface portion, which is the region from the interface between the hot-dip galvanized layer and the base steel sheet to a depth of 15 nm, and the average of the Mn/Si values of internal oxides, which are present in the region from the interface to a depth of 50-100 nm, can be 0.5 or more. Mn and Si of each oxide mean the amounts (wt %) of Mn and Si components in the oxide, which are measured by EDS, and the average of Mn/Si values means the averaged value of the Mn/Si values measured for each oxide.

公开(公告)号：US20240026488A1

公开(公告)日：2024-01-25

申请号：US18266483

申请日：2021-12-21

Applicant: POSCO Co., Ltd.

Inventor： Ki-Cheol Kang ,  Yong-Joo Kim ,  Tae-Chul Kim ,  Myung-Soo Kim ,  Jong-Sang Kim

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/38 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C21D1/74 ,  B32B15/01 ,  C23C2/02 ,  C23C2/40

CPC classification number: C21D9/46 ,  C22C38/60 ,  C22C38/38 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/008 ,  C22C38/002 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D1/74 ,  B32B15/013 ,  C23C2/02 ,  C23C2/40

Abstract: The present invention relates to a high-strength hot-dipped galvanized steel sheet having excellent surface quality and spot weldability and a method for manufacturing same. The hot-dipped galvanized steel sheet according to one aspect of the present invention comprises a base steel sheet and a hot-dipped galvanized layer formed on the surface of the base steel sheet, in which an inhibiting layer made of an Fe—Al alloy can be formed at an area ratio of 60% or more between the base steel sheet and the hot-dipped galvanized layer.

公开(公告)号：US20230002845A1

公开(公告)日：2023-01-05

申请号：US17779923

申请日：2020-12-03

Applicant: POSCO

Inventor： Ki-Cheol Kang ,  Chung-Hwan Lee

IPC: C21D9/46 ,  B32B15/01 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: The present disclosure relates to a zinc plated steel sheet having excellent fatigue strength of electrical resistance spot welds and a method for manufacturing the same. According to an aspect of the present disclosure, a zinc plated steel sheet includes a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet, wherein a concentration profile of one or two of oxygen, and silicon and manganese measured in a depth direction from the surface of the base steel sheet has a maximum point in the depth direction from the surface, and an absolute value of a difference between a depth at which the maximum point of the concentration profile of oxygen is formed and a depth at which the maximum point of the concentration profile of one of silicon and manganese is formed is 0.5 μm or less.

公开(公告)号：US10793936B2

公开(公告)日：2020-10-06

申请号：US15539669

申请日：2015-12-23

Applicant: POSCO

Inventor： Myung-Soo Kim ,  Ki-Cheol Kang ,  Jong-Ho Kim

IPC: C22C38/58 ,  C21D8/02 ,  C23C2/06 ,  C22C38/44 ,  C22C38/04 ,  C22C38/60 ,  C22C38/00 ,  C22C38/48 ,  C22C38/54 ,  C21D8/04 ,  C23C2/02 ,  C23C2/40 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C22C38/50

Abstract: A high strength galvanized steel sheet having excellent surface qualities, plating adhesion, and formability is provided, wherein a galvanized layer is formed on a cold-rolled steel sheet comprising 0.1-0.3 wt % of C, 1-2.5 wt % of Si, 2.5-8 wt % of Mn, 0.001-0.5 wt % of sol. Al, at most 0.04 wt % of P, at most 0.015 wt % of S, at most 0.02 wt % of N (excluding 0 wt %), 0.1-0.7 wt % of Cr, at most 0.1 wt % of Mo, (48/14)*[N] to 0.1 wt % of Ti, 0.005-0.5 wt % of Ni, 0.01-0.07 wt % of Sb, at most 0.1 wt % of Nb, and at most 0.005 wt % of B, with the remainder being Fe and other inevitable impurities.

公开(公告)号：US20240368796A1

公开(公告)日：2024-11-07

申请号：US18681653

申请日：2022-09-15

Applicant: POSCO CO., LTD

Inventor： Kang-Min Lee ,  Chung-Hwan Lee ,  Ki-Cheol Kang ,  Nam-A Kim ,  Yoon-Mo Jang

IPC: C25D5/50 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C25D3/12

Abstract: The present invention relates to a high-strength steel sheet having excellent surface quality due to improved coatability thereof and a method for manufacturing same.

公开(公告)号：US12054801B2

公开(公告)日：2024-08-06

申请号：US17780677

申请日：2020-12-03

Applicant: POSCO

Inventor： Ki-Cheol Kang ,  Sang-Ho Uhm ,  Chung-Hwan Lee

IPC: C21D9/46 ,  B32B15/01 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/06 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C23C2/02 ,  C23C2/022 ,  C23C2/0224 ,  C23C2/024 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C21D2241/00

Abstract: The present invention relates to a zinc plated steel sheet having excellent surface quality and spot weldability, and a manufacturing method therefore. A zinc plated steel sheet according to one aspect of the present invention comprises a base steel sheet and a zinc-based plating layer formed on the surface of the base steel sheet, wherein the GDOES profile of oxygen, which is measured in the depth direction from the surface of the base steel sheet, has a form in which a local minimum point and a local maximum point alternately appear in the depth direction from the surface, and the difference (a local maximum value−a local minimum value) between the oxygen concentration (a local minimum value) at the local minimum point and the oxygen concentration (a local maximum value) at the local maximum point can be 0.1 wt % or more.

公开(公告)号：US20240052472A1

公开(公告)日：2024-02-15

申请号：US18268149

申请日：2021-12-07

Applicant: POSCO Co., Ltd

Inventor： Ki-Cheol Kang ,  Jong-Chan Park ,  Seul-Gi So ,  Myung-Soo Kim

IPC: C23C2/06 ,  C23C2/40 ,  C21D9/46 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/06 ,  C22C38/00 ,  C21D8/02

CPC classification number: C23C2/06 ,  C23C2/40 ,  C21D9/46 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/38 ,  C22C38/06 ,  C22C38/001 ,  C21D8/0226 ,  C21D8/0273 ,  C21D8/0294 ,  C21D2211/005

Abstract: According to one aspect of the present invention, provided are a high-strength hot-dipped galvanized steel sheet having excellent surface quality and spot weldability, and a manufacturing method therefor.