Accession Number : AD0819050

Title :   TANTALUM ALLOY TUBING DEVELOPMENT PROGRAM.

Descriptive Note : Final rept. 1 Jul 63-31 Mar 67,

Corporate Author : ALLEGHENY LUDLUM STEEL CORP BRACKENRIDGE PA RESEARCH CENTER

Personal Author(s) : Turner, Fred S.

Report Date : JUL 1967

Pagination or Media Count : 162

Abstract : A process has been developed to produce tantalum alloy tubing in two alloys, Ta-10W and T-222 (Ta-9.6W-2.4HF-.01C) to each of three sizes; .500-inch OD by .062-inch wall, .375-inch OD by .062-inch wall, and .250-inch OD by .020-inch wall. The extrusion method was selected as the most economical and practical approach to producing tube hollows for subsequent tube reducing and drawing. Both the Ta-10W and T-222 alloys were extruded to 2.062-inch OD by 1.440-inch ID tube hollows from a 5-inch liner system on a 2200-ton extrusion press. Short billets of the Ta-10W alloy were successfully extruded unclad from a temperature of 2800F. Because of the additional frictional forces present, a temperature of 2800F. Because of the additional frictional forces present, a temperature of 3100F was required for longer billets. Because initial extrusions of the T-222 alloy indicated that this alloy required considerably more pressure to extrude, a molybdenum cladding technique was utilized to reduce pressures and enable us to extrude from lower temperatures. Excellent extrusions of the T-222 alloy were made using this technique from a temperature of 3000F. The main problem is in post extrusion conditioning. The tubes were roll straightened cold and conditioned by OD centerless grinding and ID boring. Many stress corrosion type cracks developed during this stage of processing. The material should be annealed or at least stress relieved between extrusion and the various conditioning operations to avoid stress cracking and extreme care should be taken in selecting coolants and lubricants.

Descriptors :   *EXTRUSION), (*TANTALUM ALLOYS, PIPES, ROLLING(METALLURGY), EXTRUSION, COLD WORKING, DRAWING(FORMING), TUNGSTEN ALLOYS, CARBON ALLOYS, CLADDING, MOLYBDENUM, ANNEALING, STRESS CORROSION, CRACKS, DUCTILITY, TENSILE PROPERTIES, RUPTURE.

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE