Irradiation-assisted SCC susceptibility of HIPed 316LN-IG stainless steel irradiated at 473 K to 1 dpa

Solid hot-isostatic pressed (solid-HIPed) joint specimens and those with or without thermal-cycled specimens of 316LN-IG were irradiated at about 473 K to 1 dpa in the high flux isotope reactor. Slow strain rate tests were conducted in a high-purity, oxygenated (dissolved oxygen=10 wt ppm) water at 423, 513 and 573 K with strain rates of (2–10)×10−7 s−1. Tensile tests were also conducted in vacuum at the same temperature range. Fracture surfaces were observed by scanning electron microscopy. No specimen showed irradiation-assisted stress corrosion cracking (IASCC) susceptibility at 423 and 513 K in water. At 573 K, however, intergranular cracks were observed to form in HIPed specimens. It was concluded that the effect of HIPing to IASCC susceptibility is small.