Effects of neutron irradiation on fracture toughness of austenitic stainless211 steels

摘要

Austenitic stainless steels are used extensively as structural alloys in reactor211u001epressure vessel internal components because of their superior fracture toughness 211u001eproperties. However, exposure to high levels of neutron irradiation for extended 211u001eperiods leads to significant reduction in the fracture resistance of these 211u001esteels. This paper presents results of fracture toughness J-R curve tests on four 211u001eheats of Type 304 stainless steel that were irradiated to fluence levels of 211u001e(approx)0.3 and 0.9 x 10(sup 21) n cm(sup (minus)2) (E > 1 MeV) at (approx)288 C 211u001ein a helium environment in the Halden heavy water boiling reactor. The tests were 211u001eperformed on 1/4-T compact tension specimens in air at 288 C; crack extensions 211u001ewere determined by both DC potential and elastic unloading compliance techniques.