公开(公告)号：US20240043980A1

公开(公告)日：2024-02-08

申请号：US18271990

申请日：2021-11-30

Applicant: NIPPON STEEL CORPORATION

Inventor： Kohei TOKUDA ,  Mamoru SAITO ,  Takuya MITSUNOBU ,  Tetsuya TOBA ,  Yasuto GOTO ,  Atsushi MORISHITA ,  Yasuaki KAWAMURA ,  Fumiaki NAKAMURA ,  Koji KAWANISHI

IPC: C23C2/06

CPC classification number: C23C2/06

Abstract: A plated steel material having a plating layer having an average chemical composition containing, in mass %, Zn: more than 50.00%, Al: more than 15.0% and less than 30.0%, Mg: more than 5.0% and less than 15.0%, and Si: 0.25% or more and less than 3.50%, and impurities, and wherein a total amount (ΣA) of at least one selected from the group consisting of Sn, Bi and In is less than 1.00%, a total amount (ΣB) of at least one selected from the group consisting of Ca, Y, La, Ce and Sr is 0.02% or more and less than 0.60%, 2.0≤SMg/Si

公开(公告)号：US20230295775A1

公开(公告)日：2023-09-21

申请号：US18040903

申请日：2021-08-19

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Hiroshi TAKEBAYASHI

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

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

Abstract: A plated steel sheet includes: a steel sheet; and a plating layer that is formed on at least a part of a surface of the steel sheet, in which a chemical composition of the plating layer includes, b mass %, Al: 6.00% to 35.00 %, Mg: 3.00% to 15.00%, La+Ce: 0.0001% to 0.5000% in total, and Zn, and in a surface of the plating layer, the area ratio of a lamellar structure in which an (Al—Zn) phase and a MgZn2 phase are arranged in layers is 10% to 95%, the lamellar spacing of the lamellar structure is 2.5 μm or less, and the area ratio of an (Al—Zn) dendrite is 10% or less.

公开(公告)号：US20230193443A1

公开(公告)日：2023-06-22

申请号：US17789753

申请日：2020-02-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Takehiro TAKAHASHI ,  Jun MAKI

IPC: C23C2/06 ,  C23C30/00 ,  C23C2/28 ,  C22C18/04 ,  C23C2/12 ,  C22C21/08

CPC classification number: C23C2/06 ,  C23C30/005 ,  C23C2/29 ,  C22C18/04 ,  C23C2/12 ,  C22C21/08

Abstract: A plated steel material 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, and in a surface structure of the plating layer, there is, by area ratio, 2.0% or more of an acicular Al—Zn—Si—Ca phase.

公开(公告)号：US20220298646A1

公开(公告)日：2022-09-22

申请号：US17636486

申请日：2020-08-28

Applicant: NIPPON STEEL CORPORATION

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

IPC: C23C30/00 ,  C22C30/02 ,  C22C30/04 ,  C22C30/06 ,  C22C22/00 ,  C22C18/04

Abstract: A hot stamped steel includes a base material, a plated layer that is formed on a surface of the base material, and an oxide film 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; and chemical composition of the oxide film contains 20.0 to 55.0 at % of Mg, 0.5 to 15.0 at % of Ca, 0 to 15.0 at % of Zn, and 0 at % or more and less than 10.0 at % of Al with a remainder of O and a total of 5.0 at % or less of impurities, and the adhesion amount of the oxide film per one surface is in a range of 0.01 to 10 g/m2.

公开(公告)号：US20200002798A1

公开(公告)日：2020-01-02

申请号：US16480976

申请日：2018-01-26

Applicant: NIPPON STEEL CORPORATION

Inventor： Kohei TOKUDA ,  Yoshinari ISHIDA ,  Takuya MITSUNOBU ,  Nobuyuki SHIMODA

IPC: C23C2/06 ,  C22C18/04 ,  C23C2/40 ,  C23C2/12

Abstract: Provided is a metallic coated steel product which is less likely to experience LME and blowhole formation and is likely to exhibit an improved corrosion resistance at welding heat affected zones. The metallic coated steel product is a hot-dip metallic coated steel product including a steel product and a plating layer that is provided on a surface of the steel product and includes a Zn—Al—Mg alloy layer. In a cross-section of the Zn—Al—Mg alloy layer an area fraction of MgZn2 phase is from 45 to 75%, a total area fraction of MgZn2 and Al phases is not less than 70%, and an area fraction of Zn—Al—MgZn2 ternary eutectic structure is from 0 to 5%; and the plating layer has a predetermined chemical composition.

公开(公告)号：US20250163557A1

公开(公告)日：2025-05-22

申请号：US18874145

申请日：2023-06-19

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Masaaki URANAKA ,  Kohei TOKUDA

IPC: C23C2/06 ,  C22C18/04

Abstract: This plated steel sheet includes a steel sheet, and a plated layer disposed on a surface of the steel sheet, in which the plated layer has a chemical composition containing, in mass %, Al: 10.0 to 25.0%, Mg: 3.0 to 10.0%, Fe: 0.01 to 2.0%, and Si: more than 0 to 2.0%, with a remainder including Zn and impurities, and a number density of Mg2Si phases having a major axis of 2 μm or more exposed on the surface of the plated layer is 3 to 150 per area of 10,000 μm2.

公开(公告)号：US20250144736A1

公开(公告)日：2025-05-08

申请号：US18833901

申请日：2023-02-07

Applicant: NIPPON STEEL CORPORATION

Inventor： Shinji KODAMA ,  Seiji FURUSAKO ,  Chisato YOSHINAGA ,  Takuya KUWAYAMA ,  Kengo TAKEDA ,  Takuya MITSUNOBU ,  Hironori SATO

IPC: B23K11/11 ,  B23K11/31 ,  B23K103/04

Abstract: This spot welding device is a spot welding device for performing spot welding on a plurality of steel sheets overlapping with each other by clamping the plurality of steel sheets between a pair of electrodes, and energizing the plurality of steel sheets while pressurizing the plurality of steel sheets, in which a speed at which the pair of electrodes approach each other is limited to at least 12.0 mm/s or slower during a period from start of the energization to end of the energization.

公开(公告)号：US20240240278A1

公开(公告)日：2024-07-18

申请号：US18288201

申请日：2021-04-27

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Keitaro MATSUDA ,  Jun MAKI ,  Takehiro TAKAHASHI ,  Hiroshi TAKEBAYASHI

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06 ,  C23C2/40

CPC classification number: C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06 ,  C23C2/40

Abstract: A steel sheet comprising, by mass %, C: 0.05 to 0.40%, Si: 0.2 to 3.0%, and Mn: 0.1 to 5.0%, wherein a surface layer of the steel sheet contains granular oxides, an average grain size of the granular oxides is 300 nm or less, a number density of granular oxides is 4.0/μm2 or more, the steel sheet comprises an Si—Mn depleted layer having a thickness of 3.0 μm or more from the surface of the steel sheet, and Si and Mn contents of the Si—Mn depleted layer not containing oxides at the ½ position of the thickness are respectively less than 10% of the Si and Mn contents at the sheet thickness center part of the steel sheet, and a plated steel sheet using the same are provided.

公开(公告)号：US20240117475A1

公开(公告)日：2024-04-11

申请号：US18274960

申请日：2022-03-14

Applicant: NIPPON STEEL CORPORATION

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

IPC: C22C38/06 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06

CPC classification number: C22C38/06 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06

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 and coarse granular 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 and 30.0/25 μm2 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：US20240093708A1

公开(公告)日：2024-03-21

申请号：US18271349

申请日：2021-12-24

Applicant: NIPPON STEEL CORPORATION

Inventor： Takuya MITSUNOBU ,  Hiroshi TAKEBAYASHI ,  Takehiro TAKAHASHI

IPC: F16B5/08 ,  B23K11/11 ,  B32B15/01 ,  B62D27/02 ,  C21D1/84 ,  C21D8/02 ,  C21D9/46 ,  C22C18/00 ,  C22C18/04 ,  C23C2/06

CPC classification number: F16B5/08 ,  B23K11/11 ,  B32B15/011 ,  B62D27/023 ,  C21D1/84 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D9/46 ,  C22C18/00 ,  C22C18/04 ,  C23C2/06 ,  B32B2250/02 ,  B32B2311/30 ,  B32B2605/08

Abstract: The present disclosure inhibits liquid metal embrittlement (LME) cracking and improves corrosion resistance 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 MgZn2 phase at the cross-section of the boundary plating layer is 10% or more, and the first plating layer and the second plating layer satisfy a predetermined Relation I.