Aluminum Alloy pipe and method of manufacturing same

Abstract

A first step of performing solution treatment to a pipe material of a precipitation-hardening type aluminum alloy of high hardness extruded, a second step of performing spinning work to the solution-treated pipe material, and a third step of performing artificial ageing to the spinning-worked pipe material.

1 - 5 . (canceled) 
   
   
       6 . An aluminum alloy pipe of high strength, comprising:
 a pipe material of a precipitation-hardening aluminum alloy of high hardness extruded, wherein:   solution treatment is performed to the pipe material by heating the pipe material to a temperature within a predetermined range;   spinning work is performed to the pipe material by pressing a roller on an outer periphery of the solution-treated pipe material while rotated; and   artificial ageing treatment is performed to the spinning-worked pipe material by heating the spinning-worked pipe material to a predetermined temperature lower than in the solution step, so that the aluminum alloy of high strength is provided, and   an outer side face and an inner side face of the aluminum alloy pipe after the artificial ageing treatment is performed thereto are nearly even in hardness; and   the outer side face of the aluminum alloy pipe is in an excessive ageing state.   
   
   
       7 . The aluminum alloy pipe according to  claim 6 , wherein:
 natural ageing treatment is performed to the solution-treated pipe material prior to the spinning work, to leave the solution-treated pipe material at a room temperature.   
   
   
       8 . The aluminum alloy pipe according to  claim 7 , wherein:
 reversion treatment is performed to the pipe material after the natural ageing treatment by reheating the pipe material prior to the spinning work.