公开(公告)号：US10946470B2

公开(公告)日：2021-03-16

申请号：US16062407

申请日：2016-12-13

Applicant: JFE STEEL CORPORATION

Inventor： Chikaumi Sawanishi ,  Koichi Taniguchi ,  Katsutoshi Takashima ,  Hiroshi Matsuda ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/16

Abstract: Provided is a resistance spot welding method that inhibits, in accordance with the degree of axis misalignment between electrodes, the occurrence of cracking in a weld regardless of the steel grade. In resistance spot welding methods according to the present invention, H (ms) is an electrode force retaining time after completion of current passage, D (mm) is an amount of axis misalignment between the electrodes, t (mm) is a total sum of sheet thicknesses of a plurality of overlapping steel sheets, T (MPa) is a tensile strength of a steel sheet having a highest tensile strength among the plurality of steel sheets, F (N) is an electrode force, and d (mm) is a tip diameter of one electrode of the pair of electrodes that has a smaller tip diameter. The electrode force retaining time H is specified to be a predetermined value or greater.

公开(公告)号：US10766099B2

公开(公告)日：2020-09-08

申请号：US15556792

申请日：2016-03-17

Applicant: JFE STEEL CORPORATION

Inventor： Muneo Matsushita ,  Koichi Taniguchi ,  Rinsei Ikeda

IPC: B23K20/12

Abstract: A friction stir welding apparatus that includes a rotary tool and a heating device. The heating device is placed in front of the rotary tool to heat steel sheets that are used as a workpiece. The rotary tool is moved in the welding direction so that steel sheet is softened by frictional heat. Additionally, the surface temperature, the area, and the position of the heated region during the heating process are strictly controlled. The heating of the steel sheets by the welding apparatus provides sufficient strength and good welding workability by advantageously eliminating plastic flow defects generated due to insufficient heating of workpieces.

公开(公告)号：US10722972B2

公开(公告)日：2020-07-28

申请号：US15555135

申请日：2016-03-03

Applicant: JFE STEEL CORPORATION

Inventor： Koichi Taniguchi ,  Yasuaki Okita ,  Rinsei Ikeda

IPC: B23K11/24 ,  B23K11/11 ,  B23K11/25 ,  B23K11/16 ,  B23K101/00 ,  B23K103/04

Abstract: A resistance spot welding device for welding at least two overlapping steel sheets held between a pair of welding electrodes is provided. The resistance spot welding device includes the pair of electrodes, an electrode force gauge that measures an electrode force, and a controller that controls an electric current supply to the electrodes according to the electrode force measured by the electrode force gauge. The controller controls the electric current such that the electrode force F measured by the electrode force gauge after the start of the electric current supply is adjusted to a prescribed value.

公开(公告)号：US10207354B2

公开(公告)日：2019-02-19

申请号：US14916269

申请日：2014-08-27

Applicant: JFE STEEL CORPORATION

Inventor： Muneo Matsushita ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/16 ,  B23K11/31 ,  B23K11/25 ,  B23K11/24 ,  B23K101/00 ,  B23K101/18 ,  B23K103/04

Abstract: In the indirect spot welding apparatus, a lower limit in a stable pressing force region where the pressing force of the spot welding electrode against the metal sheets can be controlled within a tolerance of ±10% ranges from 70 N to 200 N and an upper limit in the stable pressing force region ranges from 800 N to 2000 N, and an overshoot OS(%)=(PL−AL)/AL×100 of the pressing force occurring when the spot welding electrode is pressed against the metal sheets is controlled to be 10% or less.

公开(公告)号：US10207353B2

公开(公告)日：2019-02-19

申请号：US14783094

申请日：2014-03-06

Applicant: JFE Steel Corporation

Inventor： Muneo Matsushita ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/30 ,  B23K11/31 ,  B23K35/02 ,  B23K101/18

Abstract: An oval nugget can reliably be obtained with this indirect spot welding method. In this indirect spot welding method, an electrode end portion of a welding electrode includes a tip of the welding electrode, and as viewed from the tip, the electrode end portion has a two-step dome shape formed by a first curved surface with a curvature radius r1 (mm) located within a range of a circle of radius R (mm) centering on the tip and a second curved surface with a curvature radius r2 (mm). 2√t≤R≤6√t (1), 30≤r1 (2), and 6≤r2≤12 (3), where t is the sheet thickness (mm) of a thinner metal sheet.

公开(公告)号：US10081074B2

公开(公告)日：2018-09-25

申请号：US15317354

申请日：2015-06-05

Applicant: JFE STEEL CORPORATION

Inventor： Chikaumi Sawanishi ,  Yasuaki Okita ,  Hiroshi Matsuda ,  Rinsei Ikeda

IPC: B23K11/25 ,  B23K11/11 ,  B23K101/00 ,  B23K101/18 ,  B23K103/04

CPC classification number: B23K11/252 ,  B23K11/115 ,  B23K11/257 ,  B23K11/258 ,  B23K2101/006 ,  B23K2101/18 ,  B23K2103/04

Abstract: A resistance spot welding device that joins predetermined parts to be welded includes: a storage configured to store a time variation of an instantaneous amount of heat generated per unit volume and a cumulative amount of heat generated per unit volume in test welding that precedes actual welding; and an adaptive controller and an electrode force controller configured to, in the case where the time variation of the instantaneous amount of heat generated per unit volume in the actual welding differs from a time variation curve stored as the target value, respectively control the current or a voltage during current passage and the electrode force to the parts to be welded to compensate for the difference within a remaining welding time so that the cumulative amount of heat generated per unit volume in the actual welding matches the cumulative amount of heat generated per unit volume stored in the storage.

公开(公告)号：US09895764B2

公开(公告)日：2018-02-20

申请号：US14773017

申请日：2014-01-24

Applicant: JFE STEEL CORPORATION

Inventor： Yasuaki Okita ,  Chikaumi Sawanishi ,  Rinsei Ikeda

IPC: B23K11/11 ,  B23K11/25

CPC classification number: B23K11/115 ,  B23K11/252 ,  B23K11/255

Abstract: A resistance spot welding system includes a calculation unit that calculate and store a time variation of an instantaneous amount of heat generated, a division unit that divides a current pattern into a plurality of steps and stores a time variation of the instantaneous amount of heat generated and a cumulative amount of heat generated for each step as a target value, and an adaptive control unit that starts welding upon subsequent actual welding using, as a standard, a time variation curve of the instantaneous amount of heat generated that is stored as the target value, and adjusts welding current and voltage during welding, when a time variation amount of an instantaneous amount of heat generated deviates during any step from the time variation curve by a difference, so as to compensate for the difference during a remaining welding time in the step.

公开(公告)号：US20170348790A1

公开(公告)日：2017-12-07

申请号：US15545757

申请日：2016-01-22

Applicant: JFE Steel Corporation

Inventor： Hiroshi Matsuda ,  Yasuaki Okita ,  Muneo Matsushita ,  Rinsei Ikeda ,  Kenji Oi

IPC: B23K11/16 ,  C22C38/06 ,  B23K11/11 ,  C22C38/00 ,  C22C38/02 ,  C22C38/18 ,  C22C38/04 ,  B23K103/04

CPC classification number: B23K11/163 ,  B23K11/11 ,  B23K11/16 ,  B23K11/34 ,  B23K2103/04 ,  B32B15/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/18 ,  C22C38/60

Abstract: A steel sheet assembly includes a plurality of lapped steel sheets which have a tensile strength of 1,470 MPa or less and a thickness of 0.3 mm to 5.0 mm, the steel sheet assembly being formed by applying, in advance, an adhesive and a carbon-supplying agent to a surface of either or both of the steel sheets to be lapped and then welding the steel sheets. A weld of the assembly has a nugget diameter of 2.8√t (mm) or more, where t (mm) denotes the thickness of a thinner one of the steel sheets on both sides of a weld interface, and the amount of C is increased by 0.02 % by mass or more as compared to the steel sheets before being applied with the adhesive and the carbon-supplying agent.

公开(公告)号：US09821407B2

公开(公告)日：2017-11-21

申请号：US15025585

申请日：2014-09-10

Applicant: JFE Steel Corporation

Inventor： Muneo Matsushita ,  Koichi Taniguchi ,  Rinsei Ikeda

IPC: B23K20/12

CPC classification number: B23K20/1235 ,  B23K20/129

Abstract: A process of pre-heating treatment is performed such that steel sheets or plates as working materials are heated by a heating unit provided ahead of a rotational tool moving in a welding direction to precisely control the surface temperature, area, position and the like of a heating region in the process of pre-heating treatment when performing friction stir welding on structural steel.

公开(公告)号：US20170113295A1

公开(公告)日：2017-04-27

申请号：US15317354

申请日：2015-06-05

Applicant: JFE STEEL CORPORATION

Inventor： Chikaumi Sawanishi ,  Yasuaki Okita ,  Hiroshi Matsuda ,  Rinsei Ikeda

IPC: B23K11/25

CPC classification number: B23K11/252 ,  B23K11/115 ,  B23K11/257 ,  B23K11/258 ,  B23K2101/006 ,  B23K2101/18 ,  B23K2103/04

Abstract: A resistance spot welding device that joins predetermined parts to be welded includes: a storage configured to store a time variation of an instantaneous amount of heat generated per unit volume and a cumulative amount of heat generated per unit volume in test welding that precedes actual welding; and an adaptive controller and an electrode force controller configured to, in the case where the time variation of the instantaneous amount of heat generated per unit volume in the actual welding differs from a time variation curve stored as the target value, respectively control the current or a voltage during current passage and the electrode force to the parts to be welded to compensate for the difference within a remaining welding time so that the cumulative amount of heat generated per unit volume in the actual welding matches the cumulative amount of heat generated per unit volume stored in the storage.