Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

REMOVAL OF CARBON FROM LIQUID SODIUM SYSTEMS

Technical Report ·
OSTI ID:4810798
Carburization of austenitic stainless steels has been observed to occur readily in carbon-bearing liquid sodium at I000 deg F or higher. The high surface carbon content, 2 to 3%, caused by carburization in carbon-saturated sodium above l000 deg F can produce a brittle case on the material. The carbon content of the carburized austenitic stainless steel depends on the degree of saturation of sodium with carbon. The effects produced by carburization revealed a need for control of carbon contamination in sodium systems. lt was found that carbon could be removed effectively, either by calcium addition to sodium or by "gettering" through carburization of steel sheet in a carbon trap. The calcium addition was not considered to be immediately practical, because possible additional effects of the calcium in the system are unknown. The gettering method now is considered to be useful as a means of carbon removal. Carbon equilibrium data and diffusion data necessary for carbon trap design were determined for gettering with Type 304 and Type 4l0 stainless steels. The choice of gettering material and operating conditions will be dictated by the particular sodium system for which the trap is designed. Nomographs were constructed which relate variables pertinent to carbon traps utilizing Type 304 or Type 4l0 stainless steel. The variables included are: weight of carbon removed per unit weight of "getter", time, getter sheet thickness, carbon content of the sodium, and trap temperature. (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-16-004451
OSTI ID:
4810798
Report Number(s):
NAA-SR-6386
Country of Publication:
United States
Language:
English