Austenitic Stainless Steels for Fast Reactors -Irradiation Experiments, Property Evaluation and Microstructural Studies

Austenitic stainless steel SS316 and its variants are the common materials for the fast reactor structural components. Using the Fast Breeder Test Reactor (FBTR) as an irradiation test bed, a systematic analysis of the irradiation performance of the austenitic stainless steel has been undertaken. The performance of 20% cold worked SS316 has been assessed by examining the cladding and wrapper of FBTR at various displacement damages. The modified version of SS316, alloy D9, chosen for PFBR has been subjected to test irradiations in FBTR. Further modification of alloy D9 with respect to minor elements is also being studied The salient features of (i) mechanical and microstructural behaviour of SS316 at different fluence levels, (ii) the ongoing irradiation experiments on alloy D9 and (iii)microstructural studies on modified versions of alloy D9 are presented in this paper.