Title:
MANUFACTURE OF SQUARE STEEL TUBE
Document Type and Number:
Japanese Patent JPH04165020
Kind Code:
A
Abstract:
PURPOSE: To obtain a square steel tube of uniform quality by selectively heating corners of a square steel tube just after the square tube is formed and providing heat treatment on the corners in order to prevent the deformation of flat part and to reduce the increased hardness in corners.
CONSTITUTION: The working coil 4 for induction heating is provided between square forming stands R1-R4 and a turks head stand 3 in order to selectively heat the corners of a square steel tube just after the square tube is formed. On-line heat treatment is provided to decrease hardness in the corners of the tube and to prevent bending during the heat treatment. Therefore, the obtd. square steel tube has uniform quality.
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Inventors:
TAKAGI HIROMI
KONO KENSAKU
KATO TOMIJI
SEKINE YUKIO
SUGIMOTO YUJI
KOJIMA SHINJI
KONO KENSAKU
KATO TOMIJI
SEKINE YUKIO
SUGIMOTO YUJI
KOJIMA SHINJI
Application Number:
JP28574490A
Publication Date:
June 10, 1992
Filing Date:
October 25, 1990
Export Citation:
Assignee:
NIPPON KOKAN KK
International Classes:
B21C37/15; B21D5/12; C21D9/08; (IPC1-7): B21C37/15; B21D5/12; C21D9/08
Domestic Patent References:
| JPH01266913A | 1989-10-24 |
Attorney, Agent or Firm:
Takehiko Suzue (2 outside)