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Patent Searching and Data


Title:
PIERCER FOR PRODUCTION OF SEAMLESS STEEL PIPE
Document Type and Number:
Japanese Patent JPS5933010
Kind Code:
A
Abstract:

PURPOSE: To provide a titled device which avoids the formation of surface roughening on the inside surface of a seamless steel pipe product by the constitution wherein an inert gas introduced into a plug bar from the root end part thereof is ejected from the outside circumferential part at the forward end thereof to prevent the oxidation of the inside surface of a hollow blank pipe formed by piercing.

CONSTITUTION: This invention relates to a piercer for producing a seamless steel pipe by pressing a plug 13 mounted in the forward end part of a plug bar 12 to a billet 10 rotated and axially moved by inclined rolls and piercing the billet to obtain a hollow blank pipe, wherein a cooling water supply pipe 28 to be passed therein with cooling water in order to maintain the abrasion resistance and strength of the plug 13 by cooling the same from the inside is provided so as to be extended into the bar 12 and a gaseous N2 supply pipe 29 having the forward end connected through a connection pipe 33, a connection hole 34 and connection groove 35 to an ejection port 37 for gaseous N2 through a gaseous N2 supply pipe 36 punched in the wall of the bar 12 is provided as the inside pipe of said supply pipe. The gaseous N2 introduced through the gaseous N2 supply chamber 25 of a distributing body 23 is ejected from the ejection port 37 in the forward end part of the bar 12 in the state of piercing or in the stage of drawing after drawing of the bar 13, whereby the oxidation of the fresh inside surface is prevented.


Inventors:
ITAYA SUSUMU
Application Number:
JP14268582A
Publication Date:
February 22, 1984
Filing Date:
August 19, 1982
Export Citation:
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Assignee:
KAWASAKI STEEL CO
International Classes:
B21B19/04; B21B25/00; B21B25/04; (IPC1-7): B21B19/04; B21B25/04
Attorney, Agent or Firm:
Shuji Shiokawa