公开(公告)号：US20240124964A1

公开(公告)日：2024-04-18

申请号：US18546428

申请日：2022-03-18

Applicant: JFE STEEL CORPORATION

Inventor： Sho HIGUCHI ,  Yoshiyasu KAWASAKI ,  Tatsuya NAKAGAITO ,  Tomomi KANAZAWA ,  Shunsuke YAMAMOTO

IPC: C23C2/06 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C23C2/40

CPC classification number: C23C2/06 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/06 ,  C23C2/40 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008

Abstract: Provided is a galvanized steel sheet having a TS of 980 MPa or more, high YS, excellent ductility, strain hardenability, and hole expansion formability. A base steel sheet has a defined chemical composition and a steel microstructure as follows: area ratio of ferrite: 65.0% or less (including 0%), area ratio of bainitic ferrite: 5.0% or more and 40.0% or less, area ratio of tempered martensite: 0.5% or more and 80.0% or less, area ratio of retained austenite: 3.0% or more, area ratio of fresh martensite: 20.0% or less (including 0%), SBF+STM+2×SMA: 65.0% or more, SMA1/SMA: 0.80 or less, and SMA2/SMA: 0.20 or more.

公开(公告)号：US20230407447A1

公开(公告)日：2023-12-21

申请号：US18251422

申请日：2021-11-05

Applicant: JFE STEEL CORPORATION

Inventor： Shunsuke YAMAMOTO ,  Katsutoshi TAKASHIMA ,  Mai AOYAMA ,  Yusuke OKUMURA ,  Tomomi KANAZAWA ,  Katsuya HOSHINO ,  Hiroshi MATSUDA ,  Ei OKUMURA ,  Yoichi MAKIMIZU ,  Masaki KOBA

IPC: C23C2/02 ,  C22C33/04 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/00 ,  C21D1/74 ,  C25D5/36 ,  C25D5/48 ,  C25D3/56 ,  C23C2/28 ,  C23C2/40 ,  C23F17/00 ,  C23C28/00

CPC classification number: C23C2/02 ,  C22C33/04 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C22C38/002 ,  C22C38/001 ,  C21D1/74 ,  C25D5/36 ,  C25D5/48 ,  C25D3/562 ,  C23C2/28 ,  C23C2/40 ,  C23F17/00 ,  C23C28/34 ,  C23C28/321 ,  C21D2251/02 ,  B23K11/166

Abstract: Provided is a galvanized steel sheet with excellent resistance to cracking in resistance welding at a welded portion, even if crystal orientations of an Fe-based electroplating layer and a cold-rolled steel sheet are integrated at a high ratio at the interface between the Fe-based electroplating layer and the cold-rolled steel sheet. The galvanized steel sheet has a Si-containing cold-rolled steel sheet containing Si in an amount of 0.1 mass % to 3.0 mass %; an Fe-based electroplating layer formed on at least one surface of the Si-containing cold-rolled steel sheet with a coating weight per surface of more than 20.0 g/m2, and a galvanized layer formed on the Fe-based electroplating layer, where crystal orientations of the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet are integrated at a ratio of more than 50 % at the interface between the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet.

公开(公告)号：US20230082367A1

公开(公告)日：2023-03-16

申请号：US17760362

申请日：2020-11-19

Applicant: JFE STEEL CORPORATION

Inventor： Shunsuke YAMAMOTO ,  Shotaro TERASHIMA ,  Yuki TAKEDA ,  Michitaka SAKURAI ,  Katsuya HOSHINO ,  Yoshiyasu KAWASAKI

IPC: C21D9/46 ,  C22C38/02 ,  C22C38/38 ,  C21D1/26 ,  C22C38/12 ,  C22C38/06 ,  C22C38/00 ,  C22C38/28 ,  C22C38/32 ,  C22C38/16 ,  C21D6/00 ,  C22C38/08 ,  C23C2/02 ,  C23C2/28 ,  C23C2/40

Abstract: To obtain a high-strength hot-dip galvanized steel sheet having excellent surface appearance even in the case where a steel strip containing Mn at a predetermined ratio or more to Si is subjected to hot-dip galvanizing treatment, a method of producing a hot-dip galvanized steel sheet using a continuous hot-dip galvanizing apparatus comprises: subjecting a steel strip to annealing, by conveying it in an annealing furnace; and subjecting the steel strip discharged from a cooling zone to hot-dip galvanizing using a hot-dip galvanizing line, to obtain a hot-dip galvanized steel sheet. The steel strip has a chemical composition containing, in mass %, Mn: 1.7% or more and 3.5% or less and Si: 0.2% or more and 1.05% or less and satisfying [Si]/[Mn]≤0.30. The chemical composition, a dew point of an atmosphere in the soaking zone, and a delivery temperature of the heating zone satisfy Formula (1).

公开(公告)号：US20250102009A1

公开(公告)日：2025-03-27

申请号：US18728240

申请日：2022-11-25

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Shunsuke YAMAMOTO ,  Tomomi KANAZAWA ,  Katsuya HOSHINO ,  Hiroshi MATSUDA

IPC: F16B37/06 ,  B23K11/00 ,  B23K11/14 ,  B23K11/16 ,  B23K103/04 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C23C2/06 ,  C25D3/56 ,  C25D7/06

Abstract: A welded joint formed by performing projection welding on a high-strength coated steel sheet and a nut, includes a content of solid solution Mn in a first region in a surface layer of the steel sheet on an outermost periphery of a weld is 40% or less of a content of solid solution Mn in a second region in a central region in a thickness direction of the steel sheet on the outermost periphery of the weld, and a content of solid solution Mn in a third region in the surface layer of the steel sheet on an innermost periphery of the weld is 40% or less of a content of solid solution Mn in a fourth region in the central region in the thickness direction of the steel sheet on the innermost periphery of the weld.

公开(公告)号：US20240117517A1

公开(公告)日：2024-04-11

申请号：US18250978

申请日：2021-11-05

Applicant: JFE STEEL CORPORATION

Inventor： Shunsuke YAMAMOTO ,  Katsutoshi TAKASHIMA ,  Yusuke OKUMURA ,  Tomomi KANAZAWA ,  Katsuya HOSHINO ,  Takashi KAWANO ,  Takako YAMASHITA ,  Hiroshi MATSUDA ,  Yoichi MAKIMIZU

IPC: C25D3/20 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C25D7/06

CPC classification number: C25D3/20 ,  C21D8/0236 ,  C21D8/0257 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C25D7/0614

Abstract: Disclosed is an Fe-based electroplated steel sheet including: a Si-containing cold-rolled steel sheet containing Si in an amount of 0.1 mass % or more and 3.0 mass % or less; and an Fe-based electroplating layer formed on at least one surface of the Si-containing cold-rolled steel sheet with a coating weight per surface of 5.0 g/m2 or more, in which in an intensity profile measured by glow discharge optical emission spectrometry, a peak of emission intensity at wavelengths indicating Si is detected within a range from a surface of the Fe-based electroplating layer to more than 0.2 μm in a thickness direction and not more than a thickness of the Fe-based electroplating layer, and an average value of C concentration in a region ranging from 10 μm to 20 μm in the thickness direction from the surface of the Fe-based electroplating layer is 0.10 mass % or less.

公开(公告)号：US20230407485A1

公开(公告)日：2023-12-21

申请号：US18251269

申请日：2021-11-05

Applicant: JFE STEEL CORPORATION

Inventor： Shunsuke YAMAMOTO ,  Katsutoshi TAKASHIMA ,  Mai AOYAMA ,  Yusuke OKUMURA ,  Tomomi KANAZAWA ,  Katsuya HOSHINO ,  Hiroshi MATSUDA ,  Ei OKUMURA ,  Yoichi MAKIMIZU ,  Masaki KOBA

IPC: C23C28/02 ,  C21D9/46 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D6/00 ,  C22C33/04 ,  C21D8/02 ,  C21D1/74 ,  C25D3/20 ,  C25D5/36

CPC classification number: C23C28/021 ,  C21D9/46 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/002 ,  C22C38/001 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C22C33/04 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D1/74 ,  C21D8/0278 ,  C25D3/20 ,  C25D5/36 ,  C21D2251/02 ,  C23C2/28

Abstract: Provided is an alloyed galvanized steel sheet with excellent resistance to cracking in resistance welding at a welded portion, even if crystal orientations of an Fe-based electroplating layer and a cold-rolled steel sheet are integrated at a high ratio at the interface between the Fe-based electroplating layer and the cold-rolled steel sheet. The alloyed galvanized steel sheet has a Si-containing cold-rolled steel sheet containing Si in an amount of 0.1 mass % to 3.0 mass %; an Fe-based electroplating layer formed on at least one surface of the Si-containing cold-rolled steel sheet with a coating weight per surface exceeding 20.0 g/m2, and an alloyed galvanized layer formed on the Fe-based electroplating layer, where crystal orientations of the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet are integrated at a ratio of more than 50% at the interface between the Fe-based electroplating layer and the Si-containing cold-rolled steel sheet.

公开(公告)号：US20230160032A1

公开(公告)日：2023-05-25

申请号：US17915696

申请日：2021-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Lingling YANG ,  Yoshiyasu KAWASAKI ,  Hidekazu MINAMI ,  Tatsuya NAKAGAITO ,  Shotaro TERASHIMA ,  Shunsuke YAMAMOTO ,  Katsuya HOSHINO ,  Yuki TAKEDA

IPC: C21D9/46 ,  C23C2/40 ,  C23C2/06 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  B21C47/02

CPC classification number: C21D9/46 ,  C23C2/40 ,  C23C2/06 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  B21C47/02 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C21D2211/001

Abstract: A steel sheet having a tensile strength (TS) of 780 MPa or more and less than 1180 MPa, high LME resistance, and good weld fatigue properties. The steel sheet has a specific chemical composition and a specific steel microstructure. Crystal grains containing an oxide of Si and/or Mn in a region within 4.9 μm in a thickness direction from a surface of the steel sheet have an average grain size in the range of 3 to 10 μm, the lowest Si concentration LSi and the lowest Mn concentration LMn in the region within 4.9 μm in the thickness direction from the surface of the steel sheet and a Si concentration TSi and a Mn concentration TMn at a quarter thickness position of the steel sheet satisfy a specified formula.

公开(公告)号：US20230151451A1

公开(公告)日：2023-05-18

申请号：US17915020

申请日：2021-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Lingling YANG ,  Shotaro TERASHIMA ,  Tatsuya NAKAGAITO ,  Shunsuke YAMAMOTO ,  Katsuya HOSHINO ,  Yuki TAKEDA

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/38 ,  C22C38/60 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/10 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C22C38/38 ,  C22C38/60 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/10 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/008 ,  C22C38/005 ,  C22C38/002 ,  C22C38/001 ,  B32B15/013 ,  C21D2211/001 ,  C21D2211/005

Abstract: A steel sheet with a tensile strength (TS) of 1180 MPa or more, a member, and a method for producing them. In a region of the steel sheet within 4.9 μm in the thickness direction, a region with a Si concentration not more than one-third of the Si concentration in the chemical composition of the steel sheet and with a Mn concentration not more than one-third of the Mn concentration in the chemical composition of the steel sheet has a thickness of 1.0 μm or more. The lowest Si concentration LSi and the lowest Mn concentration LMn in the region within 4.9 μm in the thickness direction from the surface of the steel sheet and a Si concentration TSi and a Mn concentration TMn at a quarter thickness position of the steel sheet satisfy the following formula (1):


LSi+LMn≤(TSi+TMn)/4  (1).

公开(公告)号：US20240367254A1

公开(公告)日：2024-11-07

申请号：US18561353

申请日：2022-03-14

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Shunsuke YAMAMOTO ,  Katsuya HOSHINO ,  Hiroshi MATSUDA

IPC: B23K11/11 ,  B23K11/16 ,  F16B5/08

Abstract: A resistance spot welded member and a resistance spot welding method. The resistance spot welded member includes a resistance spot weld formed by resistance-spot-welding a plurality of steel sheets including at least one high strength coated steel sheet. The high strength coated steel sheet has a specific chemical composition. The at least one high strength coated steel sheet includes a coated layer, a base metal, and an Fe-based electroplated base layer interposed between the coated layer and the base metal. The amount of solute Si and the amount of solute Mn in a region on a steel sheet surface in the vicinity of the edge of the corona of the resistance spot weld are 35% or less of the amount of solute Si and 35% or less of the amount of solute Mn, respectively, at a position ¼ of the sheet thickness.

公开(公告)号：US20200032381A1

公开(公告)日：2020-01-30

申请号：US16489848

申请日：2018-03-27

Applicant: JFE STEEL CORPORATION

Inventor： Rinta SATO ,  Shunsuke YAMAMOTO ,  Satoru ANDO

IPC: C23C2/12 ,  C22C21/08 ,  C23C2/40 ,  C23C2/28

Abstract: To provide a hot-dip Al alloy coated steel sheet which is excellent in post-painting corrosion resistance and post-working corrosion resistance. Disclosed is a hot-dip Al alloy coated steel sheet comprising a coating formed by a coating layer and an interfacial alloy layer present at an interface between the coating layer and a base steel sheet, in which the interfacial alloy layer contains Mn, and the coating layer contains Mg2Si having a major axis length of 5 μm or more.