Positron annihilation studies of austenitic and ferritic/martensitic and oxide-dispersion steels were highlighted so as to emphasize the sensitivity of the technique to defect annealing as well as precipitates. The results obtained on austenitic D9 steels were discussed with a view to emphasize the role of small TiC precipitates in the matrix, which play a critical role in void-swelling behaviour. Further, the role of Ti/C ratio as well as minor alloying elements on swelling behaviour was discussed. The current focus of research was on the use of nanoclusters in oxide-dispersion steel alloys towards the suppression of void formation under irradiation. Recent results on the investigation on yttria nano-particles in Fe – model oxide dispersion ferritic steel, were presented with supporting ab initio lifetime calculations.

Defect Evolution in Steels: Insights from Positron Studies. R.Rajaraman, G.Amarendra, C.S.Sundar: Physica Status Solidi C, 2009, 6[11], 2285–90