Title:
高合金継目無鋼管の製造方法
Document Type and Number:
Japanese Patent JP4371247
Kind Code:
B2
Abstract:
Pipe-swelling can be prevented by piercing-rolling a high-alloy steel billet heated to a temperature range from 900 to 1250°C with a piercing mill equipped with main rolls having a surface roughness R max of 150 to 500 µm. A ratio (the gap W G of guide rolls/the gap W R of the main rolls) is preferably at 1.10 to 1.20. The difference (¸ P - ¸ R ) is preferably set at 0 to 3.0°, where ¸ R is an angle between an exit-side face of each of the main rolls of the piercing mill and the pass line; and ¸ P is an angle between a rolling face of the piercing plug and the pass line.
Inventors:
Kenichi Saito
Application Number:
JP2008087150A
Publication Date:
November 25, 2009
Filing Date:
March 28, 2008
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21B19/04; B21B23/00; B21B27/02; B21B27/10
Domestic Patent References:
| JP4319006A | ||||
| JP10081937A |
Foreign References:
| WO2005115650A1 |
Attorney, Agent or Firm:
Mikiji Sugioka
Terutada Hogami
Chihara
Terutada Hogami
Chihara