Title:
熱間継目無製管用Crめっきマンドレルバーおよびその製造方法
Document Type and Number:
Japanese Patent JP4196990
Kind Code:
B2
Abstract:
By employing a Cr-plated mandrel bar for producing hot seamless tubes according to the present invention wherein centerline average roughness Ra in axial and circumferential directions as well as maximum depth Rv in axial and circumferential directions is specified and further maximum height Rp in axial and circumferential is specified, surface defects such as seizure unlikely generate in an elongation-rolling process by a mandrel mill so that the service life can be dramatically extended, thereby the remarkable reduction of tool cost can be achieved. Moreover, it contributes greatly to improve the inner surface quality of hot seamless tubes to be rolled by a mandrel mill rolling process. Also, the manufacturing method by the present invention makes it possible to efficiently manufacture Cr-plated mandrel bar for producing hot seamless tubes.
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Inventors:
Junsei Iida
Toshiro Anraku
Masami Imamura
Hirofumi Hori
Toshiro Anraku
Masami Imamura
Hirofumi Hori
Application Number:
JP2005506772A
Publication Date:
December 17, 2008
Filing Date:
June 03, 2004
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21B25/00; B21B17/02
Domestic Patent References:
| JP2000246312A | ||||
| JP8071618A | ||||
| JP8164404A | ||||
| JP2001001016A | ||||
| JP2000351007A | ||||
| JP11226614A |
Attorney, Agent or Firm:
Michio Mori