Irradiation creep of stainless steels.

摘要

Irradiation creep of stainless steels has been the subject of many experimental and theoretical studies for the last 30 years. Although a vast amount of knowledge of irradiation creep has accumulated, the database on irradiation creep comes from many relatively small experiments, and there were often differences in experimental conditions from one study to the next. This has led to varied opinions on the nature of the relationship between irradiation creep and swelling. The wide variation in experimental conditions has also led to significant scatter in the data on irradiation creep in absence of swelling.;The present work contains selected portions of the author's nearly 10 year long study of irradiation creep. The study is based on the data acquired from a multi-million dollar irradiation creep experiment that was conducted in the Fast Flux Test Facility. While the experiment was designed and executed by others, the author and his mentor, F. A. Garner, were presented with the opportunity to analyze the majority of the data. The data analyzed for this thesis span nearly the entire range of irradiation conditions and materials that was covered by all previous irradiation creep experiments of stainless steels. Because all the data were obtained in a similar manner, the data contain very little scatter. This has led to a refinement of the understanding of irradiation creep. In particular, the varied opinions on the observed relationship between irradiation creep and swelling have been reconciled.;Using the current irradiation creep theories, an attempt was made to understand the new insights on the relationship between irradiation creep and swelling. One theory was found to provide an explanation, however it was realized that certain physical phenomenon were under emphasized. In particular, the theory did not include the effect of polycrystallinity on irradiation creep. An irradiation creep simulation which incorporates polycrystallinity was constructed to aid in understanding how polycrystallinity might affect the relationship between irradiation creep and swelling. The simulation showed that the effect of polycrystallinity was to reduce the overall magnitude of irradiation creep, but it did not affect the relationship between irradiation creep and swelling.