Effects of annealing on the tensile properties of irradiated austenitic stainless steel

The austenitic stainless steel (Fe-0.06C-0.5Si-1.8Mn-14Cr-16Ni-2Mo-0.24Ti) was irradiated in a triple ion facility and the high flux isotope reactor. The materials used were in the solution annealed (SA) and 15% cold-worked (CW) condition. TEM and tensile specimens were irradiated to a dose level of 30 and 10 dpa at 200 C. Some of the specimens were annealed after the irradiation at 500 C for 8 h in a vacuum. Microhardness tests were carried out on the surface of the TEM disks at room temperature. Tensile tests were carried out at 200 C in a vacuum with strain rate of about 1 x 10-3 s-1. The microhardness of both SA and CW increased by ion irradiation and then decreased by annealing. The yield strengths of the neutron irradiated SA and CW decreased to 610 and 650 MPa by annealing, respectively. The strain to necking of the irradiated CW recovered from 0.7% to 7.6%. The fracture mode remained ductile in each case. (orig.)