公开(公告)号：US20240003032A1

公开(公告)日：2024-01-04

申请号：US18039175

申请日：2021-12-09

Applicant: POSCO Co., Ltd

Inventor： Jin-Ho Jung ,  Won-Hwi Lee ,  Ki-Cheol Kang ,  Seong-Choon Kwon

IPC: C25D3/20 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D6/00 ,  C21D1/74 ,  B32B15/01 ,  C23C2/02 ,  C23F17/00 ,  C25D5/50

CPC classification number: C25D3/20 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/06 ,  C22C38/02 ,  C22C38/002 ,  C21D9/46 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D1/74 ,  B32B15/013 ,  C23C2/026 ,  C23F17/00 ,  C25D5/50

Abstract: In a steel sheet for plating, according to one aspect of the present invention, the CBS profile of an Mn element, which is observed in the direction of surface to depth, sequentially comprises local maximum points and local minimum points, difference of converted concentration of Mn can be 10% or higher, and difference of converted concentration of Si can be 10% or higher.

公开(公告)号：US20230018291A1

公开(公告)日：2023-01-19

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 ,  C21D8/02 ,  C21D6/00 ,  C22C38/60 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/44 ,  C22C38/06 ,  C22C38/58 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01 ,  C23C2/06 ,  C23C2/40

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：US11299793B2

公开(公告)日：2022-04-12

申请号：US16609017

申请日：2018-06-22

Applicant: POSCO

Inventor： Sea-Woong Lee ,  Kyoo-Young Lee ,  Joo-Hyun Ryu ,  Ki-Cheol Kang

IPC: C21D9/46 ,  C22C38/04 ,  C21D1/26 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40 ,  C23C14/16

Abstract: Provided is a steel sheet having excellent resistance to liquid metal embrittlement cracks and a method for manufacturing the same. The steel sheet includes, by weight %, 0.04% to 0.35% of C, 0.99% or less of Al+Si, 3.5% to 10% of Mn, 0.05% or less of P (excluding 0%), 0.02% or less of S (excluding 0%), and 0.02% or less of N (excluding 0%) with a remainder of Fe and other inevitable impurities, wherein the steel sheet comprises a microstructure comprising at least 10% of residual austenite, at least 60% of annealed martensite and 20% or less of alpha martensite and epsilon martensite, by volume fraction, and an average thickness of a Mn-depleted layer is at least 0.5 μm from a product surface.

公开(公告)号：US11090907B2

公开(公告)日：2021-08-17

申请号：US16471203

申请日：2017-12-22

Applicant: POSCO

Inventor： Ki-Cheol Kang ,  Hyeon-Seok Hwang ,  Yon-Kyun Song ,  Il-Jeong Park

IPC: B32B15/01 ,  C22C21/02 ,  C23C2/12 ,  C23C2/16 ,  C23C2/28

Abstract: Provided is a hot dip aluminized steel material including a base steel and a hot-dip Al—Si-coated layer, wherein the surface layer of the base steel is provided with an Al-enriched layer in which 2 wt % to 20 wt % of Al is solid-solubilized, and an interface between the base steel and the hot-dip Al—Si-coated layer has a double-layer structured interfacial alloy layer having different hardnesses.