A study has been made on the effect of hydrogen on the change of tensile properties in Uranium-10wt% Molybdenum alloy. Hydrogen was imbedded varying concentration from 1 wppm to 6 wppm. Thermal charging method was used by annealing 2 hours at 850℃ and quenched in water immediately afterwards.
It was found that the effect of hydrogen in this alloy was in principle shown in the variation of RA (Reduction in Area). The critical concentration for the ductile-brittle transition was found to be 3-4 wppm. Below the critical concentration, the change in RA was considered to agree with the IHE (Internal Hydrogen Embrittlement) theory. Above the critical concentration, an abrupt decrease was found to appear and the value of RA levels up at this value indifferent to the concentration of hydrogen. This was attributed to the saturation of the grainboundary precipitation of uranium hydride ($UH_3$) and to the inter-granular failure.
