Title:
MANUFACTURING METHOD OF SEAMLESS TUBE
Document Type and Number:
Japanese Patent JP3425718
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a manufacturing method of a seamless tube to effectively suppress generation of flaws on an inner surface without generating any defective bite in the Mannesmann pushing and boring method using a material such as free-cutting steel easy to degrade the internal material quality and high alloy steel difficult to work.
SOLUTION: In the manufacturing method of the seamless tube to allow a cast ingot of circular transverse section to bite a skew mill roll and bore it by a boring plug, the rotational speed of the skew mill roll is controlled so that the PP value defined by the following formula is positive, and the back pressure is applied to the cast ingot by a pusher until the cast ingot is stably bitten in the skew mill roll. PP=-0.00012BT+1.6856×10-5×Dr-0.000327×Vr+0.0255, where BT is the diameter (mm) of a stock billet, Dr is the diameter (mm) of the boring roll, and Vr is the rotational speed (rpm) of the roll.
Inventors:
Tatsuro Katsumura
Takashi Ariizumi
Shozo Higashi
Takashi Ariizumi
Shozo Higashi
Application Number:
JP34651499A
Publication Date:
July 14, 2003
Filing Date:
December 06, 1999
Export Citation:
Assignee:
JFE Engineering Corporation
International Classes:
B21B19/04; (IPC1-7): B21B19/04
Domestic Patent References:
| JP1228603A | ||||
| JP5261409A | ||||
| JP5950906A | ||||
| JP63220907A | ||||
| JP9300006A | ||||
| JP10175049A |
Attorney, Agent or Firm:
Takehiko Suzue (5 outside)