WELDABILITY STUDIES OF THREE COMMERCIAL COLUMBIUM-BASE ALLOYS

At the present time, a group of niobium-base alloys is being considered for addition to the Department of Defense Refractory Metals Sheet Rolling Program. Good weldability is one of the requirements for inclusion of alloys in thls program. Two alloys currently under consideration are B-66, produced by Westinghouse Electric Corporation, and FS-85, produced by Fansteel Metallurgical Corporation. A third alloy, C-129, produced by Wah Chang and submitted by Boeing Airplane Company, was also included in this evaluation. Samples of these three alloys were obtained for a brief weldability evaluation at Battelle to determine whether the alloys met the target properties established by the Materials Advisory Board, Refractory Metals Sheet Rolling Panel-Alloy Requirements and Selection Group. Room-temperature bend-ductility target properties for fabricable niobium-base alloys are lT for base metal bends and 2T for welds bent with the weld transverse to the bend axis. Bend tests made on base-metal samples showed that all alloys met the target properties for base metal. Bend tests of welds made in a vacuum-purged controlled-atmosphere chamber showed that only the welds in the FS-85 alloy possessed the desired target properties. (auth)