METHOD OF PRODUCING TITANIUM ROUND RODS WITH ULTRAFINE STRUCTURE Russian patent published in 2012 - IPC B21B3/00 C22F1/18 

FIELD: process engineering.

SUBSTANCE: proposed method comprises stage-by-stage grinding of titanium billet grains by abc-forming and multi-pass rolling in grooved rolls with stepwise reduction in groove section at fixed temperature of billet heating for rolling. Increased mechanical properties are ensured by stepwise grain grinding at stepwise temperature reduction in the range of 750-500°C. In abc-forming, titanium billets made be subjected to recrystallisation annealing at 680-700°C for 1 h. Rolling in grooved rolls is performed at reducing billet temperature by 40-60°C at every pass to groove smaller section from 500°C to 300°C whereat rod final round cross-section is formed. The number of groove cross-sections id selected to provided for reduction not exceeding 40% in transition from one groove to another. Rolling is performed in several passes on turning the billet through 90 degrees about lengthwise axis. 4-8 mm-dia round titanium billets are produced to meet high purity standards.

EFFECT: higher metal yield.

6 cl, 2 tbl, 3 ex