Title:
INCLINED ROLLING EQUIPMENT, METHOD FOR PRODUCING SEAMLESS TUBE BLANK, AND METHOD FOR PRODUCING SEAMLESS STEEL TUBE
Document Type and Number:
WIPO Patent Application WO/2021/220653
Kind Code:
A1
Abstract:
Provided is inclined rolling equipment with which a defect in the shape of an unsteady portion at the distal and proximal ends of a seamless tube blank can be prevented. This inclined rolling equipment is provided with an inclined piercing rolling mill for carrying out piercing rolling, and an inclined outer-diameter rolling mill following the inclined piercing rolling mill, wherein the distance LS (mm) between the rolling portion of the piercing rolling rolls and the rolling portion of the outer-diameter rolling rolls satisfies formula (1), and the roll interval DS of a plurality of the outer-diameter rolling rolls satisfies formula (2). (1): 3×(1.2PO+2G)≤LS≤0.8BL
(2): 1.2PO+2G>DS≥DB+2G
In formulas (1) and (2), PO is the outer diameter (mm) of the plug, G is the interval (mm) between the plug and the piercing rolling rolls, BL is the length (mm) of a bar, and DB is the outer diameter (mm) of the bar.
Inventors:
SASAKI SHUNSUKE (JP)
KATSUMURA TATSURO (JP)
KIJIMA HIDEO (JP)
KATSUMURA TATSURO (JP)
KIJIMA HIDEO (JP)
Application Number:
PCT/JP2021/010935
Publication Date:
November 04, 2021
Filing Date:
March 17, 2021
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
B21B19/04; B21B23/00; B21B38/10; B21C51/00
Foreign References:
| JP2009241075A | 2009-10-22 | |||
| JP2002331301A | 2002-11-19 |
Attorney, Agent or Firm:
KUMASAKA Akira et al. (JP)
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