MÁLEK Jaroslav UJP PRAHA a.s.

Spoluautoři HNILICA František, VESELÝ Jaroslav, ŘÍHOVÁ Zuzana

The beta-transus temperature is very important for all beta-titanium alloys during their processing. This temperature is influenced by the chemical composition of the alloy. Intersticial elements (O, N, B) can strongly influence beta-transus temperature even in very low concentration. In this work the influence of O and B elements on transition temperature has been studied. Specimens with various additions of O or B were prepared. These specimens were aged at 500 °C for 24 hours in order to obtain equilibrium α+β microstructure. Subsequently the specimens were annealed at various temperatures (with 50°C increment) and water quenched. The microstructure was then studied. At lower temperature α-precipitates coarsening has been observed and at higher temperatures precipitates dissolution took place. It was find out that oxygen addition strongly influences the transition temperature (increase approximately 410 °C/wt. %), but the effect of boron is weak (addition of 0.5 wt.% caused increase of 15 °C).