POWER REACTOR PROGRAM. Progress Report to Savannah River Operations Office, United States Atomic Energy Commission for the Period May 1, 1962-May 31, 1962

Technical Report · Tue Jun 26 00:00:00 EDT 1962

OSTI ID:4827303

Isserow, S; Anderson, R W; Richmond, W J; Davies, D M

Two outer tubes containing U-1 wt% Si and U-1.5 wt% Mo cores are being fabricated for irradiation in the HWCTR. The U-1 wt% Si tube was successfully beta treated and air cooled, and is undergoing nondestructive testing. The U-1.5 wt% Mo tube remains in the asextruded condition pending selection of a heat treatment. The hot hardness data for the dispersion hardenable U-0.035 wt% Fe-- 0.09 wt% Al alloy after aging treatments at harder than unalloyed U at test temperatures to 600 deg C, and that oil quenching from the beta phase results in a dispersion hardened condition. It was also found that the hardnesses of the alloy can be moderately increased by aging (at 400 deg C) after beta quenching, and that softening of the alloy (overaging) can occur at 500 and 600 deg C; the rate of softening is about one hundred times more rapid at 600 deg C. Modifying the U-- Fe--Al alloy with additions of Si and Cr increases the hardnesses to 600 deg C moderately. The precipitated particles are smaller and less concentrated than in the U-- Fe--Al. Evaluation of a very dilute aIIoy containing about 500 ppm total of Fe, Ni, Si, and Zr showed that the hardnesses in the 200 to 500 deg C range are susceptible to heat treatment. Heat treatments necessary to develop the properties are similar to those used to develop the delta phase'' for control of grain size. Studies of cast 0.15, 0.4, 1.0, 1.5 wt% Mo alloys before and after heat treatment for 100 hours at 540 deg C indicated that the hardness behavior of these alloys can be related to phase transformations de duced from the phase diagram and metallographic data. It was also shown that the 1.5 wt% Mo alloy exhibited the greatest microstructural and hardness stability at 540 deg C, and the hardness transition temperature of approximately 500 deg C is apparently a stable condition. The solubility limit of Mo in U was found to be less than 0.15 wt% at 540 deg C. Twelve specimens containing U--0.035 wt% Fe--0.09 wt% Al cores are being prepared for irradiation at SRP in leadinsulated capsules. A prototype tube was successfully extruded. In the extrusion of this tube and of core stock for the irradiation specimens, the metallurgical condition of the alloy markedly affected the extrusion constant. (auth)

• Research Organization: Nuclear Metals, Inc., Concord, Mass.
• DOE Contract Number: AT(30-1)-1565
• NSA Number: NSA-16-025735
• OSTI ID: 4827303
• Report Number(s): NMI-7251
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-62
• Country of Publication: United States
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
ALUMINUM ALLOYS
CASTING
CHROMIUM ALLOYS
EXTRUSION
FABRICATION
FUEL ELEMENTS
GRAIN SIZE
HARDNESS
HEAT TREATMENTS
HWCTR
IRON ALLOYS
IRRADIATION
MATERIALS TESTING
METALLOGRAPHY
MOLYBDENUM ALLOYS
NICKEL ALLOYS
PHASE DIAGRAMS
PRECIPITATION
SAVANNAH RIVER PLANT
SILICIDES
SOLUBILITY
STABILITY
TUBES
URANIUM ALLOYS
ZIRCONIUM ALLOYS