Swelling and in-pile creep behavior of some 15Cr15NiTi stainless steels in the temperature range 400 to 600 degrees

This paper reports on a pressurized tube experiment (PFR-M2) carried out in prototype fast reactor PFR in order to determine swelling and in-pile creep of commercial (Deutsches Institut fur Normung DIN1.4970 and 12RN72) and model 15Cr15Ni austenitic stainless steel alloys. Two intermediate dimensional measurements have been performed up to now, the maximum doses achieved being approximately 52 dpa(NRT) at 420 degrees C, approximately 40 dpa at 500 degrees C, and approximately 27 dpa at 600 degrees C. The combination of diameter and length measurements allowed good estimates of the stress-induced swelling by applying the Soderberg theorem. Stress-free swelling of the commercial alloys varies by about a factor of eight between the lowest and the largest swelling one. This swelling difference is attributed to a high silicon content of about 1 wt% in the former one. The stress dependence of in-pile creep is not quite linear. Swelling and in-pile creep are strongly correlated