VANADIUM ALLOY STUDIES.

This program is concerned with the improvement of rupture strength of vanadium alloys in the temperature range of 2000F to 2400F. Alloys based on V-60Cb, V-40Cb30Ta, and V-50Ta were fabricated to 0.025 in. sheet and evaluated for mechanical properties at room temperature and 2200F. Arc-melted ingots exhibited excellent cold rollability once the cast structure had been broken down, and nearly all of the alloys had more than 20 tensile elongation at room temperature. The alloy V-40Cb-30Ta1Ti-0. 235Si-0.075C had an ultimate tensile strength of 210,000 psi in the fully recrystallized condition. Roomtemperature deformation of most of the alloys was accompanied by extensive twinning. Compositions based on V-50Ta were age hardenable. Creep-rupture data obtained under a 10.000 psi load at 2200F in vacuo showed that creep rates of the experimental alloys were much lower than the dilute Cb-1Zr alloy, but were somewhat higher than current commercial columbium alloys. Creep rates for some of the experimental alloys were 0.05 inin hr during a 2 hr exposure. Author