Sumitomo Metal Industries, Inc.

Kikuchi Co., Ltd.

Sumitomo Light Metal Industries, Ltd.

Sumitomo Metal Industries Co., Ltd.

Kiyoyuki Fukui

Masanari Kimoto

Takao Minagawa

Yutaka Miyamoto

Tsutomu Yoshida

Shinichi Inagaki

Hiroshi Ikeda

Yoshihiko Hoboh

Tetsuaki Tsuda

Takao Taka

Toshiaki Shiota

Masanori Tsuji

Keizo Namba

Yukihiro Yoshikawa

Tadashi Sakane

Shinya Hikino

Yasushi Hosoda

Sachio Matsuo

Hideo Kawaguchi

Hiroki Hanabata

Toshiharu Oshiba

Yozo Hirose

Masamitsu Matsumoto

Maki Itoh

Kenji Ikishima

Kazu Uchida

Takao Aimu

Hideyuki Uto

A butt welding apparatus and a butt welding method where end faces of at least one plate member to be welded are butted to each other to form a butt portion, and butt welding can be performed on respective plate members which have various thickness sizes on both side portions of the butt portion with electric resistance heat by a pair of electrode members which are common to the respective plate members. At least one electrode member () is provided on an outer face thereof with a convex portion (A) which gradually retreats from one plate member () of two plate members () as it extends from an intermediate portion, in a thickness direction, of the one electrode member () along the one plate member (). Butt welding of the two plate members () is performed by the position of the butting portion () of these plate members () being offset from the intermediate portions, in the thickness directions, of the electrode members () to the convex portion (A) by an amount (L) corresponding to a difference in thickness between the plate members ().

Butt welding device and butt welding method

A butt welding apparatus, a butt welding method, and a product manufactured by the butt welding method involves two electrode rollers disposed on both the front and back sides of a thick sheet member and a thin sheet member whose end surfaces are butted. The electrode rollers bridge across the sheet members and are composed of small diameter portions on the side of the thick sheet member and large diameter portions on the side of the thin sheet member. The small diameter portions come into contact with and press the thick sheet member before the large diameter portions come into contact with the thin sheet member. Thus, the end surface of the thick sheet member swells and deforms toward the thin sheet member and reliably comes into contact with the end surface of the thin sheet member, and power is applied between the end surfaces, even if not polished.

Butt welding apparatus, butt welding method, and butt welded product

A coating composition comprising 38%-66% of a binder resin (including a curing agent), 0.2%-6% of an organic lubricant, 20%-50% of an iron phosphide-based electrically conductive pigment, and 3%-25% of one or more other inorganic pigments including anticorrosive pigments (the total content of these pigments being between 31% and 56%), wherein the content of the binder resin (including a curing agent) (R) and that of the organic lubricant (W) satisfy the following inequality:

Coating composition and resin-coated metal sheets

A zinc or zinc alloy electroplated metal sheet comprises a metal sheet having, on at least one surface thereof, a composite zinc or zinc alloy plated coating formed by electroplating with zinc or a zinc alloy in a plating solution which contains at least one organic compound selected from the group consisting of alkynes, alkynols, amines and salts thereof, thio compounds, heterocyclic compounds, and aromatic carboxylic acids and salts thereof. The composite plated coating has a coating weight of 0.5-200 g/m.sup.2 and contains 0.001-10 wt % of co-deposited carbon. The electroplated metal sheet has improved post-painting corrosion resistance, press formability, and spot weldability.

Composite zinc- or zinc alloy-electroplated metal sheet and method for

A multilayer plated aluminum sheet suitable for use in automobile body panels comprises a base aluminum sheet made of aluminum or an aluminum alloy and has a first layer of zinc or a zinc alloy formed by displacement plating on the surface of the aluminum sheet and one or more layers of electroplated coating formed on the first layer by electroplating in an acidic bath. Preferably, the upper electroplated coating comprises at least one layer of zinc or a zinc alloy and the uppermost layer of the coating is formed from a metallic material having a melting point above 500.degree. C.

Multilayer plated aluminum sheets

A precoated steel sheet having improved corrosion resistance and formability is disclosed, which comprises a Zn- or Zn alloy-plated steel sheet having on the plated surface either a colloidal silica-containing chromate undercoat layer and a polyhydroxypolyether resin-based topcoat of 0.3 to 10 .mu.m in thickness in which resin is derived by polycondensation of a dihydric phenol component selected from a mononuclear dihydric phenol, dinuclear dihydric phenol, and a mixture of both, with an epihalohydrin or a non-colloidal material-containing chromate underlayer and an epoxy resin based topcoat containing colloidal silica of a thickness of from 0.3-1.6 .mu.m in thickness. In spite of the absence of zinc powder, the precoated steel sheet can be satisfactorily welded by resistance welding when the thickness of the topcoat layer is not greater than 2.5 .mu.m, and even with such a thin topcoat, the precoated steel sheet retains its improved corrosion resistance and formability. The precoated steel sheet can be satisfactorily finish-coated by electrodeposition. The undercoat layer is produced by a two stage reduction of Cr.sup.+6 to Cr.sup.+3 in an aqueous suspension containing chromic acid.

Precoated steel sheet having improved corrosion resistance and

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Kobe, Japan

Kiyoyuki Fukui