Effects of alloying elements Mn, Mo, Ti, Si, P and C on the incubation period of void swelling in austenitic stainless steels

Void swelling, which induces the degradation of the original properties of nuclear materials under high-energy particle-irradiation, is an important problem. The incubation period, a transient stage before the steady void growth, determines the duration of service of nuclear materials. Several experimental studies have been performed on void observations by transmission electron microscopy (TEM), which, however, has a resolution limit for the size of defect clusters. Positron annihilation lifetime spectroscopy (PALS) enables the detection of small vacancy clusters, single vacancies, dislocations and precipitates. The use of these two methods provides complementary information toward detecting defect information in the incubation period. Here, defect structures during the incubation period in austenitic stainless steels, by means of PALS and TEM are reviewed. The role of alloying elements into determining the period is explained. Furthermore, the existing problems and research directions in this field are presented.