Creep surge effect under cyclic irradiation of structural materials for fusion reactors

Experimental investigations were performed on the radiation-creep behavior of austenitic stainless steels, α-Fe and Fe–Cr alloys. The effect of an abrupt increase of creep rate early after either switching on and switching off irradiation (radiation-induced creep surge) was revealed. The effect of electron irradiation on the thermal-activation parameters of creep was examined. The radiation creep surge effect is discussed in terms of a dynamic preference of dislocations under nonstationary conditions typical of the formation of new radiation-equilibrium flows of radiation induced point defects.