THERMOMECHANICAL PIPE TREATMENT METHOD Russian patent published in 2013 - IPC C21D9/08 C21D1/40 B21J5/04 

FIELD: metallurgy.

SUBSTANCE: pipe ends are heated up to Ac₃+(180÷230)°C; then, the pipe is fixed simultaneously at two points: in a matrix and by means of a clip at the distance of 500÷4500 mm from the upset pipe end. Upsetting of each pipe end is performed per pass of a puncheon on a horizontal forging machine with deformation degree of 20 to 67% and cooled in the air to room temperature. After cooling is finished, the pipe is subject to annealing by electrocontact heating of the whole pipe volume of up to 200-300°C.

EFFECT: providing high complex of strength properties and small-grain homogeneous structure.

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