Mechanical characterization of austenitic stainless steel ion irradiated under external stress

In a neutron irradiation field, irradiation creep takes place at temperatures far below the temperature that would cause significant thermal creep. It is expected that irradiation creep will cause the degradation of mechanical properties. The mechanical properties of type 304 stainless steel irradiated under external stress were examined using a nanoindentation technique combined with inverse analysis by a finite element method. The specimens were irradiated at a temperature of 300 °C under external stress using the triple ion beam facility. The degree of hardening for the irradiated specimen did not depend on the external stress. From the analytical results, there is little influence of applied stress on yield stress and nominal stress–strain curve of the irradiated specimen in this test condition.