公开(公告)号：EP4394076A1

公开(公告)日：2024-07-03

申请号：EP22861736.1

申请日：2022-08-25

申请人： POSCO Co., Ltd

发明人： IM, Young-Roc ,  UHM, Sang-Ho ,  KIM, Young-Ha

IPC分类号： C22C38/38 ,  C22C38/22 ,  C22C38/32 ,  C22C38/26 ,  C22C38/28 ,  C22C38/00 ,  C21D8/02 ,  B21C47/02

CPC分类号： B21C47/02 ,  C21D8/02 ,  C22C38/00 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/06

摘要： The present invention relates to: a cold rolled steel sheet having excellent weldability, strength, and formability; and a method for manufacturing same.

公开(公告)号：EP4265772A1

公开(公告)日：2023-10-25

申请号：EP21906977.0

申请日：2021-12-09

申请人： POSCO Co., Ltd

发明人： KIM, Young-Ha ,  KIM, Myung-Soo ,  MIN, Kwang-Tai ,  KANG, Ki-Cheol

IPC分类号： C22C38/04 ,  C22C38/02 ,  C22C38/06 ,  C23C2/06 ,  C21D8/02 ,  C21D9/46

摘要： An embodiment of the present invention provides a high strength hot-dip galvanized steel sheet having excellent plating adhesion and weldability and a method of manufacturing same, wherein: the steel sheet comprises a base steel sheet and a hot-dip galvanized layer formed on one surface or both surfaces of the base steel sheet, the base steel sheet comprising, in weight%, carbon (C): 0.1-0.3%, silicon (Si): 0.1-2.0%, aluminum (Al): 0.1-1.5%, manganese (Mn): 1.5-3.0%, and the balance being Fe and inevitable impurities, the sum of Si and Al satisfying 1.2-3.5%, the ratio (Al/Si) of Al and Si satisfying 0.5-2.0; the steel sheet comprises an internal oxidation layer with a thickness of 1-5 µm directly below the surface of the base steel sheet; and the decarburization rate in a region from directly below the surface of the base steel sheet to 50 µm is 50% or more.

公开(公告)号：EP4265808A1

公开(公告)日：2023-10-25

申请号：EP21906975.4

申请日：2021-12-09

申请人： POSCO Co., Ltd

发明人： KIM, Young-Ha ,  LEE, Suk-Kyu ,  HAN, Tae-Kyo ,  KANG, Dae-Young

IPC分类号： C23C2/06 ,  C23C2/02 ,  C23C2/28 ,  C23C2/40 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D8/02

摘要： One embodiment of the present invention provides a high-strength hot-dip galvanized steel sheet having excellent coatability and a manufacturing method therefor, the hot-dip galvanized steel sheet having a base steel sheet and a hot-dip galvanized layer formed on one or both surfaces of the base steel sheet, wherein the base steel sheet comprises an internal oxide layer comprising, by weight%, carbon (C): 0.1% to 0.3%, silicon (Si): 0.1% to 2.0%, aluminum (Al): 0.1% to 1.5%, manganese (Mn): 1.5% to 3.0%, and the balance being Fe and unavoidable impurities, wherein the sum of Si and Al satisfies 1.2% to 3.5%, the ratio of Al and Si (Al/Si) satisfies 0.5 to 2.0, the surface roughness (Ra) of the base steel sheet is 0.5 µm or more, and the thickness directly under the surface of the base steel sheet is less than 4 µm.