DECARBURIZATION OF CAST URANIUM CARBIDE BY HEATING IN HYDROGEN

Technical Report · Thu Aug 15 04:00:00 EDT 1963

OSTI ID:4678597

Smiley, W G; Turner, W D

The removal of excess carbon from cast UC by heating in hydrogen at 1600 to 2000 deg C was studied by means of a thermobalance with a tantalum tube furnace. At temperatures above 1800 deg C, decarburization automatically stops at the stoichiometric carbon content, because evaporation of uranium maintains constant composition. The rate of carbon removal is diffusion controlled. The diffusivity is a function of composition, increasing rapidly as the stoichiometric point is approached. In the range of carbon content from 4.95 to 5.30 wt%, the diffusivity is given by: log D == This agrees with carbon-14 measurements, but the diffusivity is larger than the self-diffusion coefficient by ahout a factor of seven. This may result from an increase in diffusivity on annealing, or it may be due to the fact that the U-- C system is far from an ideal solution. (auth)

• Research Organization: Atomics International. Div. of North American Aviation, Inc., Canoga Park, Calif.
• DOE Contract Number: AT(11-1)-GEN-8
• NSA Number: NSA-17-034408
• OSTI ID: 4678597
• Report Number(s): NAA-SR-7921
• Country of Publication: United States
• Language: English

Related Subjects

ACTIVATION ENERGY
ANNEALING
CARBON
CARBON 14
CASTING
CONTROL
DECARBURIZATION
DIFFUSION
EQUATIONS
EVAPORATION
FURNACES
HEATING
HIGH TEMPERATURE
HYDROGEN
INSTRUMENTS
MEASURED VALUES
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
TANTALUM
THERMODYNAMICS
TRACER TECHNIQUES
TUBES
URANIUM CARBIDES
WEIGHT