IMPROVED VANADIUM-BASE ALLOYS
Final rept., 1 Dec 1960-30 Nov 1961
IIT RESEARCH INST CHICAGO IL
Pagination or Media Count:
Alloys based on V-5woTi-20woCb and V-60woCb were found to exhibit excellent fabricability and weldability with good retention of strength to at least 2200 deg F. Ultimate tensile strength values of materials at the 60wo columbuim level measured under He were above 60,000 psi at 2000 deg F and up to 44,400 psi at 2200 deg F the strongest alloy at 2200 F was V-1woHf-60woCb. Materials at the 20wt- Nb level were at least 30 lower in strength at all temperatures. Stress-rupture properties at 2000 deg F of compositions based on V-5wt-Ti-20wt-Nb and V-60wt- Nb were substantially improved by addition of 0.05wt- C. interstitial impurities in the raw materials and those picked up during melting and hot working were found to reduce workability and to increase elevated-temperature strength. Tensile data obtained at elevated temperatures under vacuum were lower than those measured under He due to reduced pickup of interstitials during testing. Alloys based on V-Ti-Nb-Si exhibited interesting age-hardening characteristics at 1200 deg F. Exposure to a saline environment under stress at 800 and 1000 F did not impair the mechanical properties of V-5wt-Ti20wt-Nb, although slight pitting was observed at 1000 deg F.
- Metallurgy and Metallography