公开(公告)号：US20240093340A1

公开(公告)日：2024-03-21

申请号：US18285777

申请日：2023-03-31

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Kohei TOKUDA ,  Hiroshi TAKEBAYASHI

IPC: C23C2/06 ,  C23C2/00 ,  C23C2/40

CPC classification number: C23C2/06 ,  C23C2/40 ,  C23C2/50

Abstract: The hot-dip plated steel material includes a steel material and a hot-dip plated layer disposed on a surface of the steel material, the hot-dip plated layer has a certain chemical composition, and the hot-dip plated layer has a diffraction intensity obtained from a result of X-ray diffraction measurement, the diffraction intensity satisfying a certain relationship.

公开(公告)号：US20240058888A1

公开(公告)日：2024-02-22

申请号：US18270984

申请日：2021-12-24

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Hiroshi TAKEBAYASHI ,  Takehiro TAKAHASHI

IPC: B23K11/16 ,  B23K11/11 ,  B23K35/28

CPC classification number: B23K11/163 ,  B23K11/11 ,  B23K35/282 ,  B23K2103/04

Abstract: The present disclosure inhibits liquid metal embrittlement (LME) cracking in a welded joint obtained by spot welding a first steel sheet and a second steel sheet. In the welded joint of the present disclosure, a first plating layer is provided on a surface of the first steel sheet facing the second steel sheet, no plating layer is present on or a second plating layer is provided on a surface of the second steel sheet facing the first steel sheet, and a boundary plating layer is provided between the first steel sheet and the second steel sheet in a range of 0.5 mm from an end part of the corona bond toward an outside of the spot welded part. A higher tensile strength of a tensile strength of the first steel sheet and a tensile strength of the second steel sheet is 780 MPa or more, an area ratio of a η-Zn phase at the cross-section of the boundary plating layer is 5% or more, and the first plating layer and the second plating layer satisfy predetermined Relations I and II.

公开(公告)号：US20230399727A1

公开(公告)日：2023-12-14

申请号：US18271138

申请日：2022-03-14

Applicant: NIPPON STEEL CORPORATION

Inventor： Keitaro MATSUDA ,  Takuya MITSUNOBU ,  Masaaki URANAKA ,  Jun MAKI ,  Hiroshi TAKEBAYASHI

IPC: C22C38/38 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C21D1/84 ,  C23C2/06 ,  C23C2/40

CPC classification number: C22C38/38 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/005 ,  C22C38/002 ,  C22C38/001 ,  C21D9/46 ,  C21D8/0278 ,  C21D8/0263 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0205 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D1/84 ,  C23C2/06 ,  C23C2/40

Abstract: High strength steel sheet and plated steel sheet having high plateability, LME resistance, and hydrogen embrittlement resistance, that is, steel sheet containing C: 0.05 to 0.40%, Si: 0.2 to 3.0%, Mn: 0.1 to 5.0%, and sol. Al: 0.4 to 1.50%, having an internal oxidation layer including fine granular oxides, coarse granular oxides, and grain boundary oxides in a surface layer of the steel sheet, a number density of fine granular oxides in the internal oxidation layer being 4.0/μm2 or more, a number density of coarse granular oxides in the internal oxidation layer being 4.0/25 μm2 or more, having a Ratio A of the length of the grain boundary oxides projected on the surface of the steel sheet to the length of the surface of the steel sheet when examining a cross-section of the surface layer of the steel sheet being 50% or more and 100% or less, and including a surface depleted layer with a steel composition not including oxides which satisfies, by mass %, Si≤0.6% and Al≥0.05% at a depth of ½ of the average depth of the internal oxidation layer calculated from the cross-sectional SEM image of the steel sheet, and a plated steel sheet using the same.

公开(公告)号：US20230383392A1

公开(公告)日：2023-11-30

申请号：US18250774

申请日：2021-12-24

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Hiroshi TAKEBAYASHI

IPC: C23C2/06 ,  C22C18/04 ,  C22C38/02 ,  C22C38/04 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C21D1/74 ,  C23C2/40 ,  B32B15/01

CPC classification number: C23C2/06 ,  C22C18/04 ,  C22C38/02 ,  C22C38/04 ,  C21D9/46 ,  C21D8/0205 ,  B32B15/013 ,  C21D8/0278 ,  C21D6/005 ,  C21D6/008 ,  C21D1/74 ,  C23C2/40 ,  C21D8/0236

Abstract: A plated steel sheet for automobile structural members has a steel sheet, a plating layer formed on at least a part of a surface of the steel sheet, and an oxide layer formed on at least a part of a surface of the plating layer, the plating layer has a predetermined chemical composition, and when measurement by XPS is performed at a position 5.0 nm below a surface of the oxide layer in a thickness direction. IMg/IMgOx, which is the ratio of a maximum detected intensity of Mg to a maximum detected intensity of an oxide or hydroxide of Mg, is 0.00 or greater and 1.20 or less.

公开(公告)号：US20230235437A1

公开(公告)日：2023-07-27

申请号：US18007650

申请日：2021-03-19

Applicant: NIPPON STEEL CORPORATION

Inventor： Tetsuya TOBA ,  Atsushi MORISHITA ,  Yusuke KOHIGASHI ,  Shinichi YAMAGUCHI ,  Takuya MITSUNOBU

IPC: C23C2/06 ,  C22C18/04 ,  B32B15/01 ,  C23C2/40 ,  C23C2/28

CPC classification number: C23C2/06 ,  C22C18/04 ,  B32B15/013 ,  C23C2/40 ,  C23C2/29

Abstract: This hot-dip Zn—Al—Mg-based plated steel includes: a steel; and a plating layer formed on a surface of the steel, in which the plating layer contains, as an average composition, Mg: 1 to 10 mass %, Al: 4 to 22 mass %, and a remainder consisting of Zn and impurities, the plating layer includes an (Al—Zn mixed structure) in an area ratio of 10% to 70% in a cross section of the plating layer in a matrix of an (Al/Zn/MgZn2 ternary eutectic structure), the (Al—Zn mixed structure) includes a first region that has a Zn concentration in a range of 75 mass % or more and less than 85 mass % and a second region that is present inside the first region and has a Zn concentration in a range of 67 mass % or more and less than 75 mass %, and an area ratio of the second region in the (Al—Zn mixed structure) in the cross section of the plating layer is more than 0% and 40% or less.

公开(公告)号：US20230203635A1

公开(公告)日：2023-06-29

申请号：US18009015

申请日：2021-09-07

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Mamoru SAITO ,  Kohei TOKUDA ,  Hiroshi TAKEBAYASHI

IPC: C23C2/06 ,  C23C2/28 ,  C22C18/04

CPC classification number: C23C2/06 ,  C22C18/04 ,  C23C2/29

Abstract: A hot-dip plated steel according to one aspect includes a base steel and a hot-dip plating layer disposed on a surface of the base steel, a chemical composition of the hot-dip plating layer contains, by mass%, Al: 10.00% to 30.00%, Mg: 3.00% to 12.00%, Sn: 0% to 2.00%, Si: 0% to 2.50%, Ca: 0% to 3.00%, Ni: 0% or more and less than 0.25%, Fe: 0% to 5.00%, and the like, a remainder consists of Zn and impurities, a metallographic structure of the hot-dip plating layer contains 5 to 45 area% of an α phase having a grain diameter of 0.5 to 2 µm, the metallographic structure of the hot-dip plating layer contains 15 to 70 area% of a MgZn2 phase, and, among the α phases having the grain diameter of 0.5 to 2 µm, an area ratio of an α phase having a (111)α//(0001)MgZn2 orientation relationship to the adjacent MgZn2 phase is 25% to 100%.

公开(公告)号：US20230147056A1

公开(公告)日：2023-05-11

申请号：US17802583

申请日：2020-02-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Jun MAKI

IPC: C22C30/06 ,  B32B15/01 ,  C23C2/06

CPC classification number: C22C30/06 ,  B32B15/013 ,  C23C2/06

Abstract: A hot stamped body comprising a steel base material and an Al-Zn-Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 85.0% of an Mg—Zn containing phase and 15.0 to 90.0% of an Fe—Al containing phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg2 Zn3 phase, and MgZn2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase and an area ratio of the Fe—Al—Zn phase in the main layer is 10.0% or less.

公开(公告)号：US20230121606A1

公开(公告)日：2023-04-20

申请号：US17802736

申请日：2020-02-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Jun MAKI

IPC: C22C38/06 ,  C23C2/28 ,  C22C38/02 ,  C22C38/00 ,  C23C2/04 ,  B21D22/02

Abstract: A hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 70.0% of an Mg—Zn containing phase and 30.0 to 90.0% of an Fe—Al containing phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg2Zn3 phase, and MgZn2 phase, and the Fe—Al containing phase comprises an FeAl phase and Fe—Al—Zn phase and an area ratio of the Fe—Al—Zn phase in the main layer is more than 10.0 to 75.0%.

公开(公告)号：US20230088501A1

公开(公告)日：2023-03-23

申请号：US17802584

申请日：2020-02-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Jun MAKI

IPC: B21D22/02 ,  B32B15/01 ,  C22C18/04 ,  C23C2/06

Abstract: A hot stamped body comprising a steel base material and an Al—Zn—Mg-based plating layer formed on a surface of the steel base material, wherein the plating layer has a predetermined chemical composition, the plating layer comprises an interfacial layer positioned at an interface with the steel base material and containing Fe and Al and a main layer positioned on the interfacial layer, the main layer comprises, by area ratio, 10.0 to 90.0% of an Mg—Zn containing phase, 5.0 to less than 30.0% of an Fe—Al containing phase, and 2.0 to 25.0% of an Al—Si containing oxide phase, the Mg—Zn containing phase comprises at least one selected from the group consisting of an MgZn phase, Mg2 Zn3 phase, and MgZn2 phase, and the Fe—Al containing phase comprises at least one of an FeAl phase and Fe—Al—Zn phase.

公开(公告)号：US20220275481A1

公开(公告)日：2022-09-01

申请号：US17632553

申请日：2020-08-28

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Kohei TOKUDA ,  Takehiro TAKAHASHI ,  Hiroshi TAKEBAYASHI

IPC: C22C18/00 ,  C22C30/06 ,  C22C30/02 ,  C23C2/06 ,  C23C2/20 ,  C23C2/28 ,  C23C2/40 ,  C25D11/36

Abstract: A hot stamped steel includes a base material that is formed of steel, a plated layer that is formed on a surface of the base material, and a phosphate coating that is formed on a surface of the plated layer; chemical composition of the plated layer contains 20.00 to 45.00 mass % of Al, 10.00 to 45.00 mass % of Fe, 4.50 to 15.00 mass % of Mg, 0.10 to 3.00 mass % of Si, 0.05 to 3.00 mass % of Ca, 0 to 0.50 mass % of Sb, 0 to 0.50 mass % of Pb, 0 to 1.00 mass % of Cu, 0 to 1.00 mass % of Sn, 0 to 1.00 mass % of Ti, 0 to 0.50 mass % of Sr, 0 to 1.00 mass % of Cr, 0 to 1.00 mass % of Ni, and 0 to 1.00 mass % of Mn with a remainder of Zn and impurities; the phosphate coating consists of zinc phosphate crystals containing 5.0 to 50.0 mass % of Mg and 0.5 to 5.0 mass % of Ca; and the adhesion amount of the phosphate coating per one surface is in a range of 0.1 to 10.0 g/m2.