Piercing apparatus, plug used for piercing apparatus, and method for producing seamless steel pipe
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsKazuhiro Shimoda, Tomio Yamakawa, Kouji Yamane, Yuji Inoue, Syusuke Shimooka, Kouji Muramatsu
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Abstract
There is provided a piercing apparatus in which the occurrence of an inner surface flaw in a hollow shell is suppressed. A piercing apparatus (10) according to an embodiment of the present invention is the piercing apparatus (10) which pierces a billet (18). The piercing apparatus (10) has a plug (14). The plug (14) has a through hole (30). The through hole (30) extends along the central axis, and allows the central portion of the billet (18) being pierced to pass therethrough.
Claims18
A piercing apparatus for piercing a billet, comprising a plug having a through hole which extends along a central axis of the plug and through which a central portion of the billet being pierced is allowed to pass.
A plug used for a piercing apparatus for piercing a billet, comprising a body having a through hole which extends along a central axis of the plug and through which a central portion of the billet being pierced is allowed to pass.
A method for producing a seamless steel pipe, comprising the steps of:
- preparing a piercing apparatus comprising a plug having a through hole extending along a central axis of the plug;
- and
- piercing a billet by using the piercing apparatus while a central portion of the billet is allowed to pass through the through hole in the plug.
Dependencies are inferred from the claim text.