Title:
MANUFACTURE OF COILED STEEL PIPE
Document Type and Number:
Japanese Patent JP3243665
Kind Code:
B2
Abstract:
PURPOSE: To prevent the generation of wrinkles in the inner surface near a welded part in the inner surface by heating a pipe stock for hot rolling manufactured at a specific condition to a specific temp., executing hot-draw rolling and winding into coil-state.
CONSTITUTION: The hot-draw rolling is executed to an electric resistance welded steel pipe 12 grinding the bead on the inner surface to manufacture the coiled steel pipe. At this time, the zone of (0.3 × the pipe thickness) or more in the width in the pipe circumferential direction and 20-200μm depth in the thickness direction respectively with the welded abutting part A on the inner surface B of the steel pipe 12 as center is melted by using a TIG welding torch C, laser beam, etc. Then, this melting part is solidified to manufacture the pipe stock for hot-draw rolling. Successively, the pipe stock is heated at the prescribed temp. and the hot-draw rolling is executed and the rolled pipe is wound into the coil-state. By this method, this cold-workability can remarkably be improved.
Inventors:
Yoshihiro Watanabe
Kashiwamura Hideki
Naoki Takasugi
Kashiwamura Hideki
Naoki Takasugi
Application Number:
JP6139493A
Publication Date:
January 07, 2002
Filing Date:
February 26, 1993
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
B21B17/14; B21B23/00; B21C37/08; C21D8/10; C21D9/08; (IPC1-7): B21C37/08; C21D8/10
Domestic Patent References:
| JP60125326A | ||||
| JP2258190A | ||||
| JP5699016A | ||||
| JP5982187A | ||||
| JP6238488A |
Attorney, Agent or Firm:
Spring Inoue (1 person outside)