Irradiation dose and temperature dependence of fracture toughness in high dose HT9 steel from the fuel duct of FFTF

A void nucleation and growth based damage framework to model failure initiation ahead of a sharp notch in irradiated bcc materials

“…At these notch root radii, intergranular interactions may homogenize and mitigate the effect of grain level heterogeneity on the fracture toughness that are observed for sub-grain size notch root radii, for example in the present simulations. Further, fracture toughness has also been found to vary with irradiation temperature (Byun et al, 2013). These effects are beyond the scope of the present work and not considered here.…”

Fundamental Understanding of Ambient and High-Temperature Plasticity Phenomena in Structural Materials in Advanced Reactors

“…At these notch root radii, intergranular interactions may homogenize and mitigate the effect of grain level heterogeneity on the fracture toughness that are observed for sub-grain size notch root radii, for example in the present simulations. Further, fracture toughness has also been found to vary with irradiation temperature [160]. These effects are beyond the scope of the present work and not considered here.…”

“…Although the quasi-static fracture toughness of metals has been universally found to degrade as a result of radiation, the failure mode is temperature dependent, with brittle cleavage fracture occurring at low test temperatures [3] and an increase in the apparent ductile-brittle transition temperature (DBTT) with increasing radiation [6,158,159]. In a recent study [160], it has been shown that the irradiation temperature has a dominant effect on the fracture toughness, as opposed to irradiation dose, in the regime of moderate to high radiation doses (3-148 dpa). Brittle fracture was observed when the ferritic/martensitic HT9 steel was irradiated at temperatures below 400ºC, while ductile fracture was observed when the irradiation temperature was higher [160].…”

“…In a recent study [160], it has been shown that the irradiation temperature has a dominant effect on the fracture toughness, as opposed to irradiation dose, in the regime of moderate to high radiation doses (3-148 dpa). Brittle fracture was observed when the ferritic/martensitic HT9 steel was irradiated at temperatures below 400ºC, while ductile fracture was observed when the irradiation temperature was higher [160].…”

“…The spatial evolution of inelastic strain and defect substructure during irradiation creep deformation is discussed in detail in Chapter 5. 160 MPa at 773 K .…”