Analysis of a link of embrittlement mechanisms and neutron flux effect as applied to reactor pressure vessel materials of WWER

Evolution of microstructure and mechanical properties of VVER-1000 RPV steels under re-irradiation

“…However VVER-1000 RPV steels (especially welds) differ from VVER-440 by high Ni content that significantly enhances grain boundary embrittlement. Thus embrittlement mechanisms for VVER-1000 RPV steels significantly differ from those observed for low nickel steels, but the direct experimental results on the grain boundary segregation in VVER-1000 materials irradiated with different fluxes [31] were not received.…”

“…Number densities and average sizes. In [31] flux effect for VVER-1000 steels was studied based on the comparison of the existing literature data on the mechanical properties of materials with different chemical composition. In this results of accelerated irradiation were obtained at irradiation temperature in the range from 180 to 310°C with the further conversion to 300°C.…”

A Link between Neutron and Ion Irradiation Hardening for Stainless Austenitic and Ferritic-Martensitic Steels

“…The embrittlement of ferritic-martensitic steels under irradiation occurs by two mechanisms: hardening and non-hardening [12][13][14][15][16][17]. Embrittlement by the hardening mechanism occurs due to the radiation hardening of the material, which leads to an increase in the acting stresses in the sample or structural element.…”

“…One of the consequences of neutron irradiation, which limits the lifetime of irradiated reactor components, is radiation embrittlement. In steels with a BCC lattice, including ferritic-martensitic steels (FMS), radiation embrittlement may occur by hardening and non-hardening mechanisms [12][13][14][15][16][17]. The hardening mechanism is connected to a radiationinduced increase in the yield strength (i.e., with radiation hardening).…”

On the Modelling of Thermal Aging through Neutron Irradiation and Annealing

“…At the same time, P segregations decrease the strength of interphase boundaries (e.g., carbidematrix boundaries) or grain boundaries that makes the initiation of cleavage microcracks or intergranular brittle microcracks easier and, as a consequence, leads to material embrittlement [3,19,[26][27][28][29]. Since the above mechanism of material embrittlement does not result in its hardening, such an embrittlement mechanism is referred to as a nonhardening mechanism [26,27,30].…”