Jfe Steel Corporation

Fuji Jukogyo Kabushiki Kaisha

Subaru Corporation

Mitsubishi Paper Mills Limited

Riso Kagaku Corporation

Tokyo University of Agriculture and Technology

Mitsumi Electric Company Ltd.

Nkk Corporation

Lixil Corporation

Nakame, Inc.

Kobe Steel, Ltd.

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Dainippon Ink and Chemicals, Incorporated

Combi Co., Ltd.

Thyssenkrupp Steel Ag

Hiroshi Matsuda

Rinsei Ikeda

Chikaumi Sawanishi

Katsutoshi Takashima

Koichi Taniguchi

Yoshiyasu Kawasaki

Kazuhiro Seto

Yoshimasa Funakawa

Takeshi Yokota

Yasushi Tanaka

Hiroi Yamaguchi

Yasuaki Okita

Yasuyuki Hayakawa

Yukihiro Shingaki

Takashi Terashima

Yasunobu Nagataki

Muneo Matsushita

Masaki Koba

Yuiko Wakisaka

Hideyuki Takahashi

Jun Watanabe

Yoshihiko Ono

Kohei Hasegawa

Kaneharu Okuda

Minoru Iida

Takako Yamashita

Toshiaki Naruke

Takehisa Tsukada

Reiko Endo

Takashi Kobayashi

Takeshi Fujita

Masahiro Saito

Shinjiro Kaneko

Tatsuya Nakagaito

Yuji Yamasaki

Yoichi Makimizu

Yoshihiro Hosoya

Touru Noda

Shusaku Takagi

Masanori Nagoshi

Katsuya Hoshino

Jun Urasaki

Mai Aoyama

Masaya Morita

Hiromi Yoshitomi

Koji Idei

Fusato Kitano

Shunsuke Yamamoto

Moriaki Ono

Yoshie Obata

Toru Inazumi

Kazunori Tahara

Hiroo Kaji

Kazutoshi Iida

Tomomi Kanazawa

Akane Tanaka

Shinroku Nakao

Yoshiyasu Ishii

Kazuhiko Sato

Yoshitsugu Suzuki

Keiichi Yamamoto

Minoru Tanaka

Toshito Takamiya

Nobuyuki Nakamura

Takashi Kawano

Akio Kobayashi

Reiichi Suzuki

Saiji Matsuoka

Satoru Ando

Yusuke Fushiwaki

Akira Matsuda

Kenji Kawamura

Masanori Takenaka

Shimpei Yoshioka

Thomas Heller

Kenji Oi

Tetsuya Ashida

Takayuki Futatsuka

Yuma Honda

Taro Kizu

Yohei Enta

Mitsuo Kase

Junya Okamura

Toshihiro Shigematsu

Brigitte Hammer

Hiroshi Ozawa

Masayuki Tsubaki

Shunsuke Takahashi

Manabu Hashimoto

Sachiko Suzuki

Ichiro Muramatsu

Minoru Miyata

Jian Bian

Rolf Bode

Takeshi Murai

Rinta Sato

Günter Stich

Toshiaki Kano

Hisayuki Nagatsu

Kensuke Orito

A resistance spot weld, a resistance spot welding method, a resistance spot welded joint, and a method for manufacturing the resistance spot welded joint. In the resistance spot weld, at least one of steel sheets is a high-strength steel sheet having a prescribed chemical composition. In at least one of a nugget edge region corresponding to a faying interface, the nugget edge region has a metal microstructure including tempered martensite as a main phase. The hardness Hv of the nugget edge region and the hardness Hmw of martensite in the nugget as a whole satisfy formula (4). In at least one of a strong HAZ region corresponding to the faying interface, the hardness Hh of the strong HAZ region and the hardness Hmh of martensite in a prescribed steel sheet satisfy formula (8).

Resistance spot weld, resistance spot welding method, resistance spot welded joint, and method for manufacturing resistance spot welded joint

Provided is a resistance spot welding method by which a desired nugget diameter can be stably obtained without expulsion even when the effect of a disturbance is significant. An electrode force Fof a main current passage after an intermediate welding time Tis set based on an average value or time integration value Rof a resistance between electrodes from the start of main current passage to the intermediate welding time T.

Resistance spot welding method and weld member production method

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/m, 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.

Galvanized steel sheet, electrodeposition-coated steel sheet, automotive part, method of producing electrodeposition-coated steel sheet, and method of producing galvanized steel sheet

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/m, 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.

Alloyed galvanized steel sheet, electrodeposition-coated steel sheet, automotive part, method of producing electrodeposition-coated steel sheet, and method of producing alloyed galvanized steel sheet

A welding process used in a method of manufacturing a steel sheet assembly includes spot welding steel sheets performed for a heat time of 0.08 seconds or more using a convex electrode with a tip radius of curvature of 20 mm or more or a flat electrode such that the weld force F (kN) for initial 0.03 seconds of the heat time satisfies formula: F<0.00125×(1+0.75×t)+3 where TS (MPa) denotes an average strength of the steel sheets and represents a weighted mean value of a thickness of each of the steel sheets, and t(mm) denotes a total thickness of the steel sheets (the sum of the thicknesses of the steel sheets).

Steel sheet assembly, method of manufacturing steel sheet assembly, and spot welding process

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.

Rotating tool for double-sided friction stir welding, double-sided friction stir welding apparatus, and double-sided friction stir welding method

A resistance spot welding method comprises: performing test welding; and performing actual welding after the test welding, wherein in main current passage in the actual welding, adaptive control welding is performed, and in subsequent current passage in the actual welding, current passage is performed by constant current control with a current determined based on an electrical property between electrodes in each of main current passage in the test welding and the main current passage in the actual welding.

A gas-shielded arc welding method includes welding a steel plate having a tensile strength of 780 MPa or more while feeding a consumable electrode via a welding torch and flowing a shielding gas. The consumable electrode includes, in mass %, C: 0 to 0.20%, Si: 0 to 0.50%, Mn: 0 to 0.50%, Cr: 1.00% to 9.00%, S: 0.0020% to 0.0600%, and Ni: 0 to 0.50%. The shielding gas includes, in vol. %, at least one of COand O: 1% to 15% in total, with the remainder being Ar and unavoidable impurities. Welding is performed under the condition satisfying the relationship of 1≤{−0.05×[CO+O]}+[Cr]≤8.3, and [Cr] represents the content of Cr in the consumable electrode, and [CO+O] represents a total content of at least one of COand Oin the shielding gas.

Gas-shielded arc welding method and method for manufacturing welded structure

A power control unit mounting structure mounted on a vehicle includes an engine in an engine room at a front of the vehicle, an intake manifold disposed above the engine, a power control unit that is disposed above the engine, coupled to a cable, and controls power of a drive motor, and a toeboard cross member disposed on a toeboard. The engine and the toeboard cross member partly overlap in a projected plane along a fore-and-aft direction to provide a space behind the control unit in a front view of the vehicle. The intake manifold and the control unit are disposed within a contour of the engine in a plan view of the vehicle. The intake manifold is disposed ahead of the control unit, and portions of intake pipes of the intake manifold on both sides extend rearward and are partly opposed to both side surfaces of the control unit.

Power control unit mounting structure of vehicle

A spot welded member includes a spot weld formed by holding a sheet stack of multiple steel sheets between a pair of electrodes and spot-welding the sheet stack, in which at least one of the multiple steel sheets is a high-strength zinc-based coated steel sheet having a tensile strength of 780 MPa or more, the high-strength zinc-based coated steel sheet having a coating with an Al content of 0.5% or more by mass, and in which the heat shock region of the spot weld outwardly extending from an edge of a corona bond area includes a coated layer including an FeAl alloy layer having an average thickness of 0.3 μm or more and a zinc-based coated layer having an average thickness of 2.0 μm or more on the FeAl alloy layer at the interface between the base steel sheet of the high-strength zinc-based coated steel sheet and the coating.

Spot welded member

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 I(kA), and subsequently, a post-tempering heat treatment step in which after cooling is performed for a cooling time t(ms) shown in formula (1) below, current application is performed with a current I(kA) shown in formula (2) below for a current application time t(ms) shown in formula (3) below: 800≤t. . . formula (1), 0.5×I≤I≤I. . . formula (2), and 500≤t. . . formula (3).

Resistance spot welding method and method for producing resistance spot welded joint

A camera actuator comprises: a fixed-side member; a movable-side member provided so as to be displaced in relation to the fixed-side member, the movable-side member holding a lens unit; and a drive unit that generates drive force to displace the movable-side member within a plane including a first direction and a second direction orthogonal to the first direction, the drive unit generating as drive force a combined force obtained by combining a propulsion force that displaces the movable-side member in a specified direction that is either the first direction or the second direction, and a resistance force that resists an external force acting so as to cause the movable-side member to deviate from the specified direction.

Camera actuator, camera module, and camera mounting device

A resistance spot welding method includes: performing test welding; and performing actual welding after the test welding, wherein in subsequent current passage in the test welding, current passage is performed by constant current control under a condition: 0.5 δ Vtp/Vtm δ 2.0 when tc<800 ms; 0.5−0.3·(tc−800)/800 δ Vtp/Vtm δ 2.0−0.5·(tc−800)/800 when 800 ms δ tc<1600 ms; and 0.2 δ Vtp/Vtm δ 1.5 when tc ε 1600 ms, and wherein in main current passage in the actual welding, adaptive control welding is performed, and in subsequent current passage in the actual welding, current passage is performed by constant current control under a condition: 0.8·Itp δ Imp δ 1.2·Itp.

A high-strength steel sheet of the present invention has a specific chemical composition. Furthermore, in the steel sheet, a degree of Mn segregation in a specific region is 1.5 or less; a maximum P concentration in a specific region is 0.08 mass % or less; in a specific region, at least one specific MnS particle group is present, the number of specific MnS particle groups is 2.0 or fewer per 1 mm, and the number of specific oxide-based inclusions is 8 or fewer per 1 mm; of all oxide-based inclusions, oxide-based inclusions having a specific composition are present in a number ratio of 80% or greater; the microstructure includes, in terms of a volume fraction, 30 to 95% martensite, 5 to 70% ferrite phase, less than 30% (and 0% or greater) bainite, and less than 2.0% (and 0% or greater) austenite phase; and a tensile strength is 980 MPa or greater.

High-strength steel sheet and method for producing same

A resistance spot welding method comprises: performing test welding; and performing actual welding after the test welding, wherein the test welding is performed under each of two or more welding conditions. In the test welding, for each of the welding conditions, an electrode force parameter from when electrode force application to parts to be welded starts to when a set electrode force is reached before start of current passage and a time variation curve of an instantaneous amount of heat generated and a cumulative amount of heat generated are stored. In the actual welding: electrode force application to the parts to be welded is performed under each of the same conditions as in the test welding before start of current passage, and a corresponding electrode force parameter and the parameter stored in the test welding are compared for each of the welding conditions to set a target of a time variation curve of an instantaneous amount of heat generated and a cumulative amount of heat generated in the actual welding; and adaptive control welding is performed to control a current passage amount according to the target.

Growing community of inventors

Tokyo, Japan

Hiroshi Matsuda