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Patent Searching and Data


Title:
MANUFACTURING METHOD FOR HIGH-ALLOY SEAMLESS STEEL PIPE
Document Type and Number:
Japanese Patent JP2009241075
Kind Code:
A
Abstract:

To provide a manufacturing method for a high-alloy seamless steel pipe, which inhibits fin flaws generated in manufacturing a high-alloy seamless steel pipe by piercing.

A high-alloy steel billet heated to a temperature range of 900-1,250C is pierced and rolled by a piercer equipped with a main roll having a surface roughness Rmax adjusted to a range of 150-500 m. A ratio (an opening degree WG of a guide roll/an opening degree WR of the main roll) is preferably adjusted to a range of 1.10-1.20. The difference (P-R) between a half angle R formed by the exit face of the main roll and the pass line, and a half angle P formed by the rolling face of a piercing plug and the pass line is preferably adjusted to a range of 0-3.0.


Inventors:
SAITO KENICHI
Application Number:
JP2008087150A
Publication Date:
October 22, 2009
Filing Date:
March 28, 2008
Export Citation:
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Assignee:
SUMITOMO METAL IND
International Classes:
B21B19/04; B21B23/00; B21B27/02; B21B27/10
Attorney, Agent or Firm:
Mikiji Sugioka
Terutada Hogami
Chihara