METHOD OF PRODUCTION OF LOCKLESS DRILL PIPE OF ALUMINIUM ALLOY Russian patent published in 1997 - IPC

FIELD: thermomechanical treatment of metals in metallurgy. SUBSTANCE: the method consists in hollow blank casting, diffusion annealing, extrusion with pressing of outside and inside beaded ends, heat treatment, dressing and cutting to the nominal size; after heat treatment radial reductions of one end of the blank and radial spacing of the other are performed at a creep temperature making up 0.2 to 0.65 of the melting point of the pipe material, and at the working stress, with subsequent cooling in water; then protectors are screwed on in the form of a steel tapered shell with an extruded thread, whose standard size corresponds to the standard sizes of the pipe threads, and the pipe ends are heated to the creep temperature. EFFECT: facilitated procedure. 3 cl