HOT DUCTILITY OF TITANIUM-ALLOYS - A COMPARISON WITH CARBON-STEELS

Characteristics of hot ductility of various kinds of titanium alloys were examined and compared with that of carbon steels. Although carbon steels have three typical embrittling zones above 900 K, titanium alloys do not show any embrittlement in the temperature range between beta transus and 1 500 K, which is considered to be best region for hot rolling. The embrittlement occurs just below the beta transus in the coarse grain titanium alloys. The ductility is poor in the coarse grain materials, but independent of the strain rate. The mechanism of the embrittlement is considered to be due to the accumulation of strain in the beta phase attached to the grain boundary alpha in alpha and alpha + beta alloys.