Nisshin Steel Co., Ltd.

Nippon Steel Corporation

Nippon Steel Nisshin Co., Ltd.

Tadaaki Miono

Yasunori Hattori

Shinichi Kamoshida

Takeshi Shimizu

Yasushi Fukui

Minoru Saito

Masanori Matsuno

Hiroshi Tanaka

Kazushi Sakamoto

Yasumi Ariyoshi

Mitsuru Suzuki

Seiji Sasabe

Atsushi Andoh

Tsuguyasu Yoshii

Shinichi Koga

Tetsu Iwase

Kazunari Nakamoto

Provided is a hot-dip plating method that achieves good plating wettability between a metal material and a hot-dip plating bath and that makes it possible to reduce the amount of consumed energy as compared to conventional techniques. In a plating step included in the hot-dip plating method, vibration is applied to a hot-dip plating bath such that the ratio of the average sound pressure level (excluding noise) over ranges each lying between sound pressure peaks at harmonic frequencies of a fundamental frequency to the average sound pressure level (excluding noise) over the measured frequency range in an acoustic spectrum is greater than 0.2.

Hot-dip plating method

A method of producing an Al plated steel wire comprises a first step of continuously immersing a material steel wire formed of a steel core into a molten Al plating bath and then withdrawing the material steel wire to a gas phase space. The material steel wire plated with a plating metal is brought into contact with a contact member at the plating bath rising portion to produce the Al plated steel wire, the Al plated steel wire having an average diameter D(mm) and a minimum diameter D(mm) in the longitudinal direction of the wire satisfying the following expression (1)()/&#x2264;0.10,&#x2003;&#x2003;(1).The Al plated steel wire is then wound.

Method for producing molten Al plated steel wire

A method for producing a hot-dip aluminum-coated steel wire, including dipping a steel wire in molten aluminum, and drawing up the steel wire from the molten aluminum, wherein at the time of drawing up the steel wire from the molten aluminum, a stabilization member is contacted with a surface of the molten aluminum and the steel wire at the boundary between the steel wire and the surface of the molten aluminum, a nozzle having a tip end of which inside diameter is 1 to 15 mm is disposed so that the tip end is positioned at a place away from the steel wire by a distance of 1 to 50 mm, and an inert gas having a temperature of 200 to 800&#xb0; C. is blown out from the tip end to the boundary at a volume flow rate of 2 to 200 L/min.

Method for producing a hot-dip aluminum-coated steel wire

A crimp terminal includes an F-type crimp portion and a C-type crimp portion. The F-type crimp portion has first and second barrel tabs, preferably with an identical length, for crimping a tip end of a complex stranded wire. The F-type crimp portion is adapted to have distal ends of the first and second barrel tabs put together and pushed into the tip end of the complex stranded wire to be crimped. The C-type crimp portion has a third barrel tab for crimping the complex stranded wire. The third barrel tab is wound in a C-form on an outer periphery of the complex stranded wire to be crimped. The arrangement provides a crimp terminal and an electric wire with crimp terminal, that prevents or reduces increases in retained resistance at a crimp portion, and can also prevent an electric wire from slipping out of a crimp terminal.

Crimp terminal and electric wire with crimp terminal

A connector includes a crimping portion () provided at an inner surface with projections () having inclined sides (), the crimping portion () being provided with a combination of a base portion () and first and a second protruding portions () and () protruding from the base portion (), the first protruding portion () having a distal end part () located at an inside of a distal end part () of the second protruding portion (), the crimping portion () having a ring-shaped section perpendicular to a length direction of the aluminum electric wire (), the projections () being projected into surface areas of the aluminum electric wire (), with distorted regions formed along the inclined sides () in a surface part of the aluminum electric wire ().

Aluminum electric wire connecting structure

A steel/aluminum welded structure comprises a hot-dip Al-coated steel sheetspot welded with an aluminum or aluminum alloy sheet. The steel sheetis coated with a coating layercontaining, by mass, 3-12% of Si and 0.5-5% of Fe. An area ratio of an Al&#x2014;Fe binary alloy layer, formed at the joint boundary, is controlled to 90% or less. An unalloyed regionexists between an Al&#x2014;Fe&#x2014;Si ternary alloy layerat an interface of a steel substratewith the coating layerinterface and the Al&#x2014;Fe binary alloy layer at the joint boundary. A steel substratepreferably contains 0.002-0.020% of N for formation of a N-enriched surface layer in contact with the coating layer. The N-enriched layer impedes propagation of the brittle Al&#x2014;Fe binary alloy layer to the whole of the joint boundary and raises joint strength of the steel/aluminum welded structure.

Steel/aluminum welded structure

A Zn-Mg binary coating layer formed on a steel sheet has the tri-layered structure that the first sublayer composed of a Zn-Mg alloy having Mg concentration of 0.5 wt. % or less, the second sublayer composed of a Zn-Mg alloy having Mg concentration of 7 wt. % or more and the third sublayer composed of a Zn-Mg alloy having Mg concentration of 0.5 wt. % or less are successively laminated. The coating layer may have the penta-layered structure wherein sublayers composed of a Zn-Mg alloy having Mg concentration of 2-7 wt. % are additionally interposed between the high-Mg and low-Mg sublayers. A Zn-Fe or Zn-Fe-Mg alloy layer may be formed at the boundary between the substrate steel and the coating layer. The adhesion ratio of the first sublayer to the top sublayer is preferably 1.2 or more, while the high-Mg sublayer is preferably conditioned to the mixed structure of a Zn.sub.2 Mg phase with a Mg-dissolved Zn phase. Due to the specified lamellar structure, the intrinsic properties of the high-Mg sublayer is sufficiently exhibited, and the secondary paint adhesiveness of the coating layer is excellent. Consequently, the coated steel sheet is useful as structural members or parts exposed to a severe corrosive atmosphere in various industrial fields.

Steel sheet coated with Zn-Mg binary coating layer excellent in

A Mg source 3 is received in a vessel 1 having an opening 8, and the vessel 1 is heated at 670.degree. C. or higher to effuse Mg vapor through the opening 8. Since the vessel 1 is filled with Mg vapor, Mg is evaporated from molten state under stable condition without fluctuations in evaporation speed. The Mg vapor is effectively consumed for vapor deposition. A reflector plate may be provided at the outlet of the opening 8, or a duct for introducing Mg vapor from the vessel to the surface of a substrate sheet may be provided. In order to evaporate Mg from stabilized molten state, operational conditions are preferably determined so as to satisfy the relationships of W.sub.1 /W.sub.2 &lt;0.6.times.(P.sub.Mg /V.sup.3) and W.sub.1 /W.sub.2 &lt;0.04.times.P.sub.Mg, wherein W.sub.1 represents the area (mm.sup.2) of the opening 8, W.sub.2 represents the evaporation surface area (mm.sup.2) of the Mg source 3, P.sub.Mg represents Mg vapor pressure (torr.) and V represents the degree of vacuum.

Formation of magnesium vapor with high evaporation speed

A Zn--Mg binary coating layer formed on a steel sheet has the tri-layered structure that the first sublayer composed of a Zn--Mg alloy having Mg concentration of 0.5 wt. % or less, the second sublayer composed of a Zn--Mg alloy having Mg concentration of 7 wt. % or more and the third sublayer composed of a Zn--Mg alloy having Mg concentration of 0.5 wt. % or less are successively laminated. The coating layer may have the penta-layered structure wherein sublayers composed of a Zn--Mg alloy having Mg concentration of 2-7 wt. % are additionally interposed between the high-Mg and low-Mg sublayers. A Zn--Fe or Zn--Fe--Mg alloy layer may be formed at the boundary between the substrate steel and the coating layer. The adhesion ratio of the first sublayer to the top sublayer is preferably 1.2 or more, while the high-Mg sublayer is preferably conditioned to the mixed structure of a Zn.sub.2 Mg phase with a Mg-dissolved Zn phase. Due to the specified lamellar structure, the intrinsic properties of the high-Mg sublayer is sufficiently exhibited, and the secondary paint adhesiveness of the coating layer is excellent. Consequently, the coated steel sheet is useful as structural members or parts exposed to a severe corrosive atmosphere in various industrial fields.

Steel sheet coated witn Zn-Mg binary coating layer excellent in

A steel strip is cleaned by sputtering-etching with ion beams of argon. By the sputtering-etching, an oxide film of easily oxidable elements such as chromium and silicon is removed. The cleaned steel strip is hot-dipped.

Growing community of inventors

Osaka, Japan

Tadaaki Miono