Title:
FIXED DIAMETER ROLLING METHOD FOR SEAMLESS PIPE
Document Type and Number:
WIPO Patent Application WO/2011/148613
Kind Code:
A1
Abstract:
A three-roll fixed diameter rolling machine is used, and when the external diameter processing degree (ρi) (%) of an (i)th stand is represented by formula (1) below, fixed diameter rolling is carried out under conditions such that the external diameter processing degree ratio (R), represented by formula (2) below, is within the range of 0.95-1.05. Formula (1): ρi= [ { (Bi-1 + Ai-1) - (Bi+Ai) } / (Bi-1 + Ai-1) ] x 100… In formula (1), Ai, Ai-1 : the distance between the flange edge of a grooved roll and the pass centre in each of the (i)th stand and (i-1)th stand, and Bi, Bi-1 : the distance between the groove base of a grooved roll and the pass centre in each of the (i)th stand and (i-1)th stand. Formula (2): R= ΣρEven／ΣρOdd… In formula (2), ΣρEven: the sum total of the external diameter processing degree (ρi) of the even numbered stands, and ΣρOdd: the sum total of the external diameter processing degree (ρi) of the odd numbered stands. Thus, the thickness distribution in the circumferential direction of the pipe produced can be made to be uniform.
Inventors:
SENDAI YUSUKE (JP)
Application Number:
PCT/JP2011/002871
Publication Date:
December 01, 2011
Filing Date:
May 24, 2011
Export Citation:
Assignee:
SUMITOMO METAL IND (JP)
SENDAI YUSUKE (JP)
SENDAI YUSUKE (JP)
International Classes:
B21B17/14; B21B27/02
Foreign References:
| JPH07214111A | 1995-08-15 | |||
| JP2000334504A | 2000-12-05 | |||
| JP2006088167A | 2006-04-06 | |||
| JP2000158015A | 2000-06-13 |
Attorney, Agent or Firm:
MORI, Michio et al. (JP)
Michio Mori (JP)
Michio Mori (JP)
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