EP 0566223 B1 19960131 - Method for manufacturing seamless pipes by the plug rolling process
Title (en)
Method for manufacturing seamless pipes by the plug rolling process
Title (de)
Verfahren zum Herstellen nahtloser Rohre nach dem Stopfenwalzverfahren
Title (fr)
Procédé pour la fabrication de tubes sans soudure par le procédé de laminage à mandrin
Publication
Application
Priority
DE 4213276 A 19920416
Abstract (en)
[origin: EP0566223A1] The invention relates to a method for manufacturing seamless tubes by the plug rolling process, in which a hollow ingot is expanded and stretched in at least two passes over a fixed plug supported on a bar, in a roll stand with a closed groove, giving a tube blank, the blank being pulled off from the bar in a direction opposite to the rolling direction by means of a driver unit after each pass and being rotated through 90 DEG about the longitudinal axes before the following pass, the plug being changed after each pass. In order to modify a plug rolling method of conventional type in such a way that it is possible to dispense with the smoothing roll units and the reheating furnace, it is proposed that, in the case of a plurality of successive passes, the spacing of the rolls is varied at least in one of the passes, preferably the first, in the region of the groove base to give a wall thickness which takes account of the drawing out of this wall region in the subsequent rolling pass, ensuring a uniform wall thickness of the finished plug blank over its circumference.
IPC 1-7
IPC 8 full level
B21B 17/12 (2006.01)
CPC (source: EP US)
B21B 17/12 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0566223 A1 19931020; EP 0566223 B1 19960131; DE 4213276 A1 19931021; DE 4213276 C2 19960523; DE 59301525 D1 19960314; US 5412974 A 19950509
DOCDB simple family (application)
EP 93250081 A 19930312; DE 4213276 A 19920416; DE 59301525 T 19930312; US 4905993 A 19930416