MANUFACTURE OF SEAMLESS STEEL TUBE AND DEVICE FOR PIERCING BILLET

摘要

PROBLEM TO BE SOLVED: To provide a method and device for manufacturing a seamless steel tube by which the life of a plug used for piercing is drastically prolonged. ;SOLUTION: In the manufacturing method of the seamless steel tube including hot piercing stage, at the time of piercing a material 1 to be rolled, the deformation resistance (k) of the material 1 to be rolled at its rolling temp. is predetermined, also, using the plug 3 on which a hole 4 for jetting a fluid to the head part for pushing the piercing bottom of the material 1 to be rolled or the head part and trunk part and the fluid is jetted from this hole 4 at the pressure (suitable range: 0.6-2.5k) which is set corresponding to the (k) during piercing.;COPYRIGHT: (C)1998,JPO