Jfe Steel Corporation

Yuji Sugimoto

Tomohiro Inoue

Takatoshi Okabe

Kazuhito Kenmochi

Hiroyasu Yokoyama

Hiroyuki Shirosawa

Muneyoshi Murakami

Kei Sakata

Kenichi Iwazaki

Yasuo Nishida

Nobuyuki Matsuo

Tetsuro Sawaki

Tatsuo Koide

Osamu Shiotani

Yoshifumi Fujioka

Motoaki Egi

A method of manufacturing an electric resistance welding pipe is provided in which a lateral edge shape is made to be an appropriate shape immediately before electric resistance welding is performed, whereby penetrators are securely removed during the electric resistance welding and, consequently, an electric resistance welding pipe having excellent characterization of welded seam can be obtained. A fin shape in finpass forming is printed to lateral edges of a strip, whereby the lateral edges of the strip are shaped with predetermined tapering.

Method of manufacturing electric resistance welding pipe having excellent characterization of welded seam

A method of efficiently manufacturing electric resistance welding pipes having excellent characterization of welded seams is provided, by which each lateral edge of a rounded strip immediately before electric resistance welding is securely shaped with desired tapering flexibly in response to change in strip thickness, so that welding quality may be kept to be excellent. A method of manufacturing electric resistance welding pipes, in which a strip is subjected to forming, then edges thereof are formed to substantially face each other, and then the edges are subjected to electric resistance welding to form a pipe, wherein an edge and an edge opposed thereto at one of an upper-surface side and a lower-surface side of the strip are shaped with tapering before the forming by means of cutting or shaving, or finpass forming.

Method of manufacturing electric resistance welding pipes having excellent characterization of welded seams

Manufacturing equipment of electric resistance welding pipes having excellent characterization of welded seams, includes an apparatus that supplies a strip, an apparatus that reforms a shape, an apparatus that performs roll forming, an induction heater, and a contacting apparatus of strip edges by pressing, and having a finpass forming apparatus incorporating a fin having at least two stages of tapering in a middle portion of the roll forming, wherein tapering of the strip immediately before electric resistance welding is conducted such that an angle from a surface of a strip edge toward a vertical direction is in a range of 25 degrees to 50 degrees, and length of a perpendicular angle from a starting position to an end position of the tapering at one side is 20% to 45% of strip thickness, and by shaping the tapering with a fin, having at least two stages of tapering, incorporated in a finpass forming end stand.

Manufacturing equipment for electric resistance welding pipes having excellent characterization for welded seam

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Tokyo, Japan

Yuji Sugimoto