EP 0542387 B1 19940921 - Method of longitudinal rolling seamless pipes.
Title (en)
Method of longitudinal rolling seamless pipes.
Title (de)
Verfahren zum Längswalzen nahtloser Rohre.
Title (fr)
Procédé de laminage longitudinal de tubes sans soudure.
Publication
Application
Priority
DE 4138178 A 19911115
Abstract (en)
[origin: EP0542387A1] The invention relates to a method for the longitudinal rolling of seamless steel pipes (8) in a continuous rolling operation via an internal tool (2) in a multi-stand roll train, the rolls of the successive roll stands being installed offset relative to one another. In order to specify a method in which elongation sufficient to allow the production of double lengths of pipe with the minimum number of roll stands can be achieved, it is proposed that, in a first pass of just two successive rolling passes, a reduction in the wall thickness corresponding to or slightly less than the wall thickness of the finished pipe be made in the base (6) of the roll groove with the flanks (5) of the roll groove open, that, in the second roll pass, the flank region of the first roll pass be reduced in the transverse direction to the wall thickness of the finished pipe in the base of the roll groove of the second rolling pass, the circumferential enlargement of the tube due to the widening being reduced by stretching the pipe along its longitudinal axis without a reduction in wall thickness or with a slight reduction in wall thickness, by the simultaneous application of a controlled tensile force on the pipe between the two rolling passes. <IMAGE>
IPC 1-7
IPC 8 full level
B21B 17/02 (2006.01); B21B 17/04 (2006.01); B21B 17/08 (2006.01); B21B 37/00 (2006.01); B21B 37/28 (2006.01)
CPC (source: EP US)
B21B 17/04 (2013.01 - EP US)
Designated contracting state (EPC)
AT DE FR GB IT
DOCDB simple family (publication)
EP 0542387 A1 19930519; EP 0542387 B1 19940921; AT E111788 T1 19941015; CZ 283112 B6 19980114; CZ 331992 A3 19930616; DE 4138178 A1 19930527; DE 4138178 C2 19930826; DE 59200537 D1 19941027; JP H05237515 A 19930917; JP H08243 B2 19960110; RU 2097155 C1 19971127; US 5357773 A 19941025
DOCDB simple family (application)
EP 92250328 A 19921110; AT 92250328 T 19921110; CS 331992 A 19921105; DE 4138178 A 19911115; DE 59200537 T 19921110; JP 32473292 A 19921110; RU 92004380 A 19921113; US 15995193 A 19931129