抄録
In order to investigate the effect of alloying elements on the hydrogen embrittlement of vanadium at moderate temperatures, the metal was alloyed up to about 20 atomic per cent with molybdenum as an endothermic occluder and with titanium as an exothermic occluder, respectively, and then the specimens were hydrogenated up to about 10 atomic per cent of hydrogen. The specimens were tensile tested in the temperature range from room temperature to 573 K. Results obtained were as follows:
(1) Both of molybdenum and titanium increased the solubility limit of hydrogen in vanadium, which was measured by the internal friction method.
(2) The alloying elements deteriorated vanadium for hydrogen embrittlement, by increasing the strength and lowering the ductility.
(3) Therefore, the ductile-brittle transition temperature (DBTT) of hydrogenated alloys, which was determined as a temperature at which just half of the reduction in area of unhydrogenated specimen was obtained in the hydrogenated specimen, was located in the solid solution region as to hydrogen as well as alloying elements at moderate temperatures in phase diagrams.
(4) The brittle fracture mode was different between V-Mo and V-Ti alloys; in the former alloy brittle fracture occurred in the cleavage mode, while the intergranular fracture mode took place in the latter alloy.
