TUBE PRODUCTION METHOD Russian patent published in 1998 - IPC

FIELD: manufacture of tubes of hard-to-deform metals by extrusion. SUBSTANCE: method of making tubes of hard-to-deform metals and alloys comprises steps of selecting mean radius value of tubular blank at taking to account predetermined mean radius of ready tube according to next relation where - mean radius of tubular blank, mm; R_meantube= R_1tube+ R_2tube/ 2 - mean radius of ready tube, mm; R_1bl , R_2bl , R_1tube , R_2tube - outer and inner radius values of tubular blank and ready tube respectively, mm; μ- Poisson efficient of tube material; ψ^* - dimension-free parameter defining mechanical and physical properties of tube material; - relative parameter defining thickness of wall of ready tube; B = . EFFECT: elimination of afterdeformation rupture of extruded tubes caused by residual stresses. 2 dwg