Effect of stress on hydrogen solubility and the low temperature deformation characteristics in vanadium containing hydrogen

Abstract

The effect of applied stress near the yield stress on the dissolution temperature of hydrides in vanadium has been investigated by transmission electron microscopy (TEM) and by resistivity measurements. 1. (1) The dissolution temperature of hydrides in thin foil TEM specimens increases by 5 (0.036at.%) to 16 K (0.5 at.%) by the external tensile stress. 2. (2) In wire specimens, the change in the dissolution temperature by the external stress is within the accuracy of experiments (~ 1 K). Although the estimate by the conventional theory is in apparent agreement with the resistivity result on wire specimens, it is suggested that the TEM result on thin foil specimens should be regarded as better representing the effect of the external stress. In order to clarify the role of hydrides in the mechanical strength at low-temperatures, the elastic limit and the resistivity of wire specimens have been measured simultaneously. It is concluded that the hardening is due to hydrogen clustering along moving dislocations.