METHOD OF MANUFACTURING HOLLOW BILLETS WITH NON-OXIDIZED INNER SURFACE Russian patent published in 1994 - IPC

FIELD: metallurgy. SUBSTANCE: method involves the steps of: continuous casting of a hollow billet at periodic dispensing of it from a mould upwardly, feeding the billet for deformation and deforming. After leaving the mould the billet is pinched and cut above the pinched point. Further supplying for pressing is carried out in a vertical position without turning over, pressing being carried out from below upwardly. Thus an inert gas within the hollow billet during the whole process of casting-deforming is kept. To produce billets with alternative cavities a needle is introduced into and withdrawn out of the die opening, time of placing the needle in the die opening and time of placing the needle outside the die opening being determined from the expression given in the invention description. EFFECT: enhanced efficiency. 2 cl, 10 dwg