公开(公告)号：US12194562B2

公开(公告)日：2025-01-14

申请号：US16980098

申请日：2019-03-20

Applicant: JFE Steel Corporation

Inventor： Muneo Matsushita ,  Rinsei Ikeda ,  Hiroshi Matsuda ,  Daiki Yamagishi

IPC: B23K20/00 ,  B23K20/12

Abstract: Disclosed are rotating tools for double-sided friction stir welding that are applied to double-sided friction stir welding, which is a technique for welding two metal plates by rotating a pair of rotating tools, which oppose each other, in opposite directions, a double-sided friction stir welding apparatus that uses the rotating tools, and a double-sided friction stir welding method. A pair of rotating tools for double-sided friction stir welding that are used in double-sided friction stir welding, which is a technique for welding metal plates by using a pair of rotating tools that are each disposed on one of first and second surfaces of an unwelded portion of the metal plates such that the rotating tools rotate in opposite directions, include end portions each of which is formed in a circular and planar shape. The end portions are each made of a material harder than the metal plates.

公开(公告)号：US11992892B2

公开(公告)日：2024-05-28

申请号：US16967193

申请日：2019-02-05

Applicant: JFE Steel Corporation

Inventor： Reiko Endo ,  Muneo Matsushita ,  Koichi Taniguchi ,  Hiroshi Matsuda ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/16 ,  B23K11/24 ,  B23K101/00 ,  B23K101/18 ,  B23K103/04 ,  C21D6/00 ,  C21D9/50 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: B23K11/115 ,  B23K11/16 ,  B23K11/24 ,  C21D6/004 ,  C21D9/50 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  B23K2101/006 ,  B23K2101/18 ,  B23K2103/04

Abstract: The present invention provides a resistance spot welding method. A resistance spot welding method according to the present invention in which a sheet combination of two or more overlapping steel sheets is sandwiched between a pair of electrodes and joined together by applying current while applying pressure, the method including a main current application step in which current application is performed with a current Iw (kA), and subsequently, a post-tempering heat treatment step in which after cooling is performed for a cooling time tct (ms) shown in formula (1) below, current application is performed with a current It (kA) shown in formula (2) below for a current application time tt (ms) shown in formula (3) below: 800≤tct . . . formula (1), 0.5×Iw≤It≤Iw . . . formula (2), and 500≤tt . . . formula (3).

公开(公告)号：US11427880B2

公开(公告)日：2022-08-30

申请号：US16765708

申请日：2018-08-20

Applicant: JFE Steel Corporation

Inventor： Hiromi Yoshitomi ,  Yasuaki Okita ,  Masaki Koba ,  Hiroshi Matsuda ,  Yoshihiko Ono

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/60 ,  C23C2/06 ,  C23G1/00

Abstract: A high-strength galvanized steel sheet is excellent in the external appearance of plating and the hydrogen brittleness resistance, and has a high yield ratio, and a method for manufacturing the same. The high-strength galvanized steel sheet including a steel sheet having a specific component composition and a specific steel structure, the amount of diffusible hydrogen in the steel sheet being 0.20 mass ppm or less; and a galvanizing layer provided on a surface of the steel sheet, the galvanizing layer having a content amount of Fe of 8 to 15% in mass %, and an attachment amount of plating per one surface of 20 to 120 g/m2, wherein the amount of Mn oxides contained in the galvanizing layer is 0.050 g/m2 or less; and the high-strength galvanized steel sheet has a yield strength of 700 MPa or more and a yield strength ratio of 65% or more and less than 85%.

公开(公告)号：US20200291499A1

公开(公告)日：2020-09-17

申请号：US16765708

申请日：2018-08-20

Applicant: JFE Steel Corporation

Inventor： Hiromi Yoshitomi ,  Yasuaki Okita ,  Masaki Koba ,  Hiroshi Matsuda ,  Yoshihiko Ono

IPC: C21D9/46 ,  C21D8/02 ,  C23G1/00 ,  C23C2/06 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/60

Abstract: There is provided a high-strength galvanized steel sheet excellent in the external appearance of plating and the hydrogen brittleness resistance, and has a high yield ratio suitable for building materials and automotive collision-resistant parts, and a method for manufacturing the same.Provided is a high-strength galvanized steel sheet including a specific component composition and a specific steel structure, the amount of diffusible hydrogen in the steel being 0.20 mass ppm or less; and a galvanizing layer provided on a surface of the steel sheet, having a content amount of Fe of 8 to 15% in mass %, and an attachment amount of plating per one surface of 20 to 120 g/m2, wherein the amount of Mn oxides contained in the galvanizing layer is 0.050 g/m2 or less, and a yield strength is 700 MPa or more and a yield strength ratio is 65% or more and less than 85%.

公开(公告)号：US10773334B2

公开(公告)日：2020-09-15

申请号：US15566344

申请日：2016-04-15

Applicant: JFE STEEL CORPORATION

Inventor： Chikaumi Sawanishi ,  Hiroshi Matsuda ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/25 ,  B23K103/04 ,  B23K101/18

Abstract: A stored time variation curve and cumulative amount of heat generated of each step are each used as a target. In the case where a time variation of an instantaneous amount of heat generated per unit volume differs from the time variation curve in any of the steps, a current passage amount is controlled in order to compensate for the difference within a remaining welding time in the step so that a cumulative amount of heat generated per unit volume in actual welding matches the stored cumulative amount of heat generated in the test welding. Further, in the case where expulsion is detected in any of the steps, then in subsequent welding, the cumulative amount of heat generated per unit volume used as the target is reduced, and the current passage amount is adjusted in accordance with the reduced cumulative amount of heat generated per unit volume.

公开(公告)号：US10711333B2

公开(公告)日：2020-07-14

申请号：US15516698

申请日：2015-10-29

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu Kawasaki ,  Hiroshi Matsuda ,  Takeshi Yokota ,  Takako Yamashita ,  Kazuhiro Seto

IPC: C21D9/46 ,  C22C38/14 ,  C23C2/12 ,  C22C38/60 ,  C23C2/02 ,  C22C38/00 ,  C23C2/06 ,  C23C2/28 ,  B32B15/01 ,  B32B15/18 ,  B32B15/20 ,  C21D1/26 ,  C21D6/00 ,  C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C23C2/40 ,  C23F17/00 ,  C25D3/22

Abstract: Disclosed is a steel sheet having a predetermined chemical composition and a steel microstructure that contains, in area ratio, 15% or more and 55% or less of polygonal ferrite and 15% or more and 30% or less of martensite, and that contains, in volume fraction, 12% or more of retained austenite, in which the polygonal ferrite, the martensite, and the retained austenite have a mean grain size of 4 μm or less, 2 μm or less, and 2 μm or less, respectively, and each have a mean grain aspect ratio of 2.0 or less, and in which a value obtained by dividing an Mn content in the retained austenite in mass % by an Mn content in the polygonal ferrite in mass % equals 2.0 or more.

公开(公告)号：US10662495B2

公开(公告)日：2020-05-26

申请号：US15326116

申请日：2015-08-05

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu Kawasaki ,  Hiroshi Matsuda ,  Kazunori Tahara ,  Takeshi Yokota ,  Kaneharu Okuda ,  Kazuhiro Seto

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C22C38/60 ,  B32B15/01 ,  C21D1/60 ,  C21D8/02 ,  C22C38/02 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23G1/00

Abstract: Disclosed is a high-strength steel sheet having a tensile strength (TS) of 780 MPa or more and excellent in ductility, fatigue properties, stretch flangeability, surface characteristics, and sheet passage ability that can be obtained by providing a predetermined chemical composition and a steel microstructure that contains, by area, 20-50% of ferrite, 5-25% of bainitic ferrite, 1-10% of martensite, and 5-15% of tempered martensite, and that contains, by volume, 10% or more of retained austenite, in which the retained austenite has a mean grain size of 2 μm or less, a mean Mn content in the retained austenite in mass % is at least 1.2 times the Mn content in the steel sheet in mass %, the retained austenite has a mean free path of 1.2 μm or less, and the tempered martensite has a mean free path of 1.2 μm or less.

公开(公告)号：US10214793B2

公开(公告)日：2019-02-26

申请号：US14764650

申请日：2014-02-18

Applicant: JFE STEEL CORPORATION

Inventor： Hiroshi Matsuda ,  Hideyuki Takahashi ,  Hiroi Yamaguchi ,  Yukihiro Shingaki ,  Yasuyuki Hayakawa ,  Takashi Terashima

IPC: C23C8/50 ,  C21D8/12 ,  H01F1/16 ,  C21D6/00 ,  C21D9/46

Abstract: Provided is a method for nitriding a grain-oriented electrical steel sheet which is very useful in obtaining excellent magnetic properties with no variation by immersing a strip in a molten salt bath after cold rolling and before secondary recrystallization annealing during a production process of a grain-oriented electrical steel sheet, to subject the strip to continuous nitriding to uniformly disperse inhibitor forming elements over the full length and full width of the strip.

公开(公告)号：US20140096876A1

公开(公告)日：2014-04-10

申请号：US14100438

申请日：2013-12-09

Applicant: JFE Steel Corporation

Inventor： Hiroshi Matsuda ,  Yoshimasa Funakawa ,  Yasushi Tanaka

IPC: C21D8/02

CPC classification number: C21D8/0247 ,  C21D1/22 ,  C21D8/0205 ,  C21D9/46 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

Abstract: A method for manufacturing a high strength press-formed member includes preparing a steel sheet having the composition including by mass %: C: 0.12% to 0.69%, Si: 3.0% or less, Mn: 0.5% to 3.0%, P: 0.1% or less, S: 0.07% or less, Al: 3.0% or less, N: 0.010% or less, Si+Al: at least 0.7%, and remainder as Fe and incidental impurities, heating the steel sheet to a temperature of 750° C. to 1000° C. and retaining the steel sheet in that state for 5 seconds to 1000 seconds; subjecting the steel sheet to hot press-forming at a temperature of 350° C. to 900° C.; cooling the steel sheet to a temperature of 50° C. to 350° C.; heating the steel sheet to a temperature in a temperature region of 350° C. to 490° C.; and retaining the steel sheet at temperature in the temperature region for 5 seconds to 1000 seconds.

Abstract translation: 制造高强度压制构件的方法包括制备具有质量％：C：0.12％至0.69％，Si：3.0％以下，Mn：0.5％〜3.0％，P：0.1的组成的钢板 ％以下，S：0.07％以下，Al：3.0％以下，N：0.010％以下，Si + Al：0.7％以上，剩余部分为Fe和杂质，将钢板加热至 750℃至1000℃，并将钢板保持在该状态5秒至1000秒; 在350℃至900℃的温度下对钢板进行热压成型; 将钢板冷却至50〜350℃的温度。 将钢板加热至350〜490℃的温度范围。 并将钢板在温度区域中保持5秒至1000秒的温度。

公开(公告)号：US12221705B2

公开(公告)日：2025-02-11

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 ,  C21D1/74 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C33/04 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C23C2/02 ,  C23C2/26 ,  C23C2/28 ,  C25D3/20 ,  C25D5/36 ,  C23C2/06 ,  C23C2/40

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.