| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling the structure of a metallic tube which is suitable to produce a tube material as an industrially general using material applied with large strain deformation. SOLUTION: A structure control unit 1 provided with a mandrel 11 provided with a truncated cone-state part 12 and a large diameter shaft part 13 connected with an obtuse angleθat the interval with the peripheral surface 12a of this truncated cone-state part, a ring shaped die 16 disposed by forming a tube blank passage 19 at the interval with the large diameter shaft part, working parts 3 provided with a plurality of working rolls 17 formed as almost hourglass-state disposed by forming a working passage 20 communicated with the tube blank passage 19 at the interval with the peripheral surface 12a of the truncated cone-state part and pushing-in parts 5, 6 for pushing the metal-made tube blank 2 in the axial direction to this working part, is used. The large strain deformation changing at least the tube diameter of the tube blank 2 are repeatedly applied to the tube blank 2 by continuously giving a shearing deformation to this tube blank 2 with an ECAP method at the above obtuse angle portion while reciprocatively passing the tube blank 2 through this unit 1. COPYRIGHT: (C)2004,JPO |
