Abstract
Austenitic stainless steel is used for internal structures of nuclear reactor pressure vessel because it has high corrosion resistance and moderate fracture toughness. The fracture toughness of irradiated stainless steel is difficult to obtain due to limitation of specimen size and showed eminent scatter. On the other hand, tensile strength is relatively easy to obtain and its variation was relatively small in comparison with the fracture toughness. In order to predict the fracture toughness from the tensile strength fracture toughness tests were conducted together with full-field strain measurement around the crack tip using digital image correlation technique. The material used was a cold worked stainless steel imitating the irradiation hardening. The critical strain near the crack tip was for ductile crack initiation was identified. Based on the results obtained it was concluded that the fracture toughness is possible to be predicted using the critical strain in numerical simulation.
