EFFECTS OF HYDROGEN ON THERMALLY ACTIVATED DISLOCATION-MOTION IN IRON

In a study of decarburized Armco iron and an Fe-0.17wt.%Ti alloy, ther mal activation parameters such as m and A* were measured, in both the presence and the absence of dissolved hydrogen. It was found that hyd rogen did not significantly alter the thermal activation parameters. S ince it is accepted that thermally activated dislocation motion in iro n is controlled by Peierls-Nabarro barriers at low temperatures, this finding means that hydrogen predominantly affects the now stress of ir on through its interaction with other solutes such as carbon and titan ium. This is consistent with fundamental deformation studies on iron a s well as with previous work on hydrogen effects in iron.