Nanoscale compositional changes in Cr-Mn steels alpha-bombarded at 773 K
The structural materials for nearer-term fusion reactors are likely to be steels. During their operation, the radiation damage in the structural components will become very complex. As long as no fusion device for material testing exists, data concerning the formation of radiation damage in candidate steels can only be obtained by the use of simpler irradiating conditions, such as by neutrons with mixed energy spectra, protons and/or alphas. The present work deals with a study of the three Cr-Mn steels AMCR 0033, AMCR and Nitronic 32, implanted with 1000 appm He in the Ispra cyclotron at 773 K. Examination in a Philips 400T-FEG electron microscope indicated a different microstructure according to the type of steel. In AMCR 0033 and Nitronic 32, Frank interstitial loops of about 100 nm diameter were observed, together with small He bubbles, while in the steel AMCR a high number of very small He bubbles was present. In AMCR 0033 the bubbles were often in the form of colonies both in the matrix and on the loops. EDS nanoanalyses showed remarkable compositional changes at the bubble colonies, probably as a consequence of segregation phenomena. The implementation of morphological and structural investigations with nanoanalysis shows that by increasing the analytical spatial resolution a more complex radiation pattern for Cr-Mn steels is revealed, even for conditions simpler than those encountered in fusion reactor irradiation.
Bibliographic Reference: Paper presented: Twelfth International Congress for Electron Microscopy, Seattle (US), August 12-18, 1990
Availability: Available from (1) as Paper EN 35515 ORA
Record Number: 199011187 / Last updated on: 1994-12-01
Original language: en
Available languages: en