Screening test for duct pad materials of fuel assembly (I); Frictional coefficient in a sodium environment

Mizobuchi, Shotaro*; not registered; Koakutsu, Toru; Atsumo, Hideo

We have been conducted experiments to select for the contacting and sliding material use in F.B.R.. In present study, we tested in simulated condition for 6 kind of the candidated materials as duct pad of fuel assembly. The following results were obtained, (1)SUS316 showed a bad frictional behivor as the high frictional coefficient of 0.8, and hard chrome plating, also, have been unstable frictional behavior and become to the lower hardness after tested in 540C sodium. (2)The brush-finished chrome carbide showed the more stable frictional behaivor than the grinder-finished material, and frictional coefficient showed approximately 0.5. This coefficient was independent on the temperature in this test. (3)Colmonoy No.6 indicated the lowest frictional coefficient of 0.34 in materials of present studys. But, stellite No.6 showed a little unstable friction behavior even if tested in 280C sodium. (4)Each of tested materials were observed increasing frictional coefficient, after tested dwelling in 540C sodium. It was recognized that colmonoy No.6 and the brush-finished chrome carbide seem to be the promising as duct pad materials.