MANUFACTURING METHOD OF THIN-WALLED PIPES MANUFACTURING Russian patent published in 2010 - IPC B21C1/00 

FIELD: metallurgy.

SUBSTANCE: method includes tubes drawing bevel draw die on fixed cylindrical mandrel. High accuracy of pipes dimensions, excluding action after drawing of out-contact plasto-elastic deformation, is provided ensured by graduation of outer diametre of pipe is implemented by drawing, diametre of finishing part which is accepted as equal to D_draw=D(1+0.035logλ), where D - nominal external diametre of finished pipe, λ - elongation ratio by section of pipe, graduation of pipe inner diametre is implemented by straight plug, diametre of which is accepted equal to D_man ⁼d(1+0,025logλ), where d - nominal inner diametre of finished pipe, herewith elongation ratio by section of pipe λ is 1.25≤λ≤1.48, and elongation ratio by wall of pipe λ_s is 0.90λ≤λ_s≤0.94λ.

EFFECT: invention provided for dimensional accuracy increasing of section of thin-walled precision pipes at its manufacturing in preference for envelopes fuel elements of nuclear reactors from corrosionproof steels.