EVALUATION OF A HIGH-STRENGTH COLUMBIUM ALLOY (AS-55) FOR ALKALI METAL CONTAINMENT. Interm Report, November 25, 1961-July 25, 1962

Technical Report · Thu Oct 31 04:00:00 EST 1963

OSTI ID:4688157

Carlson, R G; Miketta, D N; Frank, R G; Semmel, Jr, J W

Fourteen 6 to 12-pound arc-cast ingots of AS-55 niobium alloy were melted to establish the melting characteristics of the alloy and to provide material for TIG welding, mechanical properties (especially long time stress- rupture properties), and potassium corrosion investigations. In general, all of the ingots melted for the program under a rather wide range of conditions were considered to be of high quality. The alloy is considered to be highly weldable, and post-weld heat treatments of 2200 to 2400 deg F were effective in retaining excellent low-temperature (- 100 deg F) weld bend ductility after l00-hour aging treatments in the temperature range 1400 to 1800 deg F. Considerable contamination by oxygen ard carbon was found to occur in stressrupture specimens after 1000 hours of testing at 2200 deg F in cold wall, uncold trapped, oil diffusion pumped vacuum channbers at pressures of 3 x 10/sup -6/ torr. Short- time tests (< 100 hours) indicate the material to have similar rupture properties to those determined for material produced previously. Potassium corrosion reflux capsule tests were conducted on AS-55 and Nb--1Zr alloys at 2000 and 2200 deg F for 1000 and 250 hours, respectively. The tests were run in getter-ion pumped vacuum chambers at pressures of 10/sup -8/ torr. Five- and ten-thousand hour 2000 deg F capsule tests of AS-55, D-43, and Nb- 1Zr are currently underway. (auth)

• Research Organization: General Electric Co. Spacecraft Dept., Cincinnait
• NSA Number: NSA-17-041339
• OSTI ID: 4688157
• Report Number(s): GE-62FPD365
• Country of Publication: United States
• Language: English

Related Subjects

ALKALI METALS
CARBON
CORROSION
DUCTILITY
FAILURES
FUEL CANS
HEAT TREATMENTS
HIGH TEMPERATURE
IMPURITIES
IONS
LOW TEMPERATURE
MATERIALS TESTING
MECHANICAL PROPERTIES
MELTING
METALS, CERAMICS, AND OTHER MATERIALS
NIOBIUM ALLOYS
OXYGEN
POTASSIUM
STRESSES
TENSILE PROPERTIES
TRAPS
VACUUM
WELDING