To provide a method for producing an + type titanium alloy member having a tensile strength of 1,000 MPa class or above, which has a Young's modulus of 75 to 125 GPa.
The + type titanium alloy having a composition containing, by mass%, 4.4 to 5.5% Al, 1.4 to 2.1% Fe and 2.5 to 5% Mo, and in which, as impurities, the content of Si is suppressed to 0.1% and the content of C is suppressed to 0.01%, and the balance Ti with inevitable impurities is cooled from a temperature of 860 to 940C at a cooling rate equal to or above that of water cooling so as to regulate its Young's modulus to 75 to 90 GPa, is cooled from a temperature of 810 to 860C at a cooling rate above that of water cooling so as to regulate its Young's modulus to 90 to 100 GPa, is cooled from a temperature of 800 to 940C so as to regulate its Young's modulus to 100 to 115 GPa, is heated at 800 to 940C and is thereafter heated at 450 to 600C for 3 to 5 hr so as to regulate its Young's modulus to 115 to 125 GPa.
OTSUKA HIROAKI
MORI KENICHI
FUJII HIDEKI
KAWAKAMI SATORU
Hisataka Tanaka