COMBINED APPARATUS FOR ROLLING SEAMLESS TUBES

摘要

The present invention relates to a plant (10) for rolling a seamless tube. The plant comprises a rotary piercer (20) which is designed to pierce a billet (11) pressed against a plug (22) mounted on a rod so as to obtain a pierced blank (12). The rod is connected to a thrust block (26) designed to oppose the axial thrust which is produced on the rod during piercing. The plant also comprises a longitudinal mill (30) which is designed to roll the pierced blank (12) on a mandrel (32) so as to obtain a semi-finished tube (13). The mandrel is connected to a retaining block (34) designed to impart to the mandrel a predetermined speed during rolling. In the plant according to the invention the thrust block (26) and the retaining block (34) are formed by a single thrust/retaining block (36). The invention also relates to a method for rolling a seamless tube.