Micromechanical testing of unirradiated and helium ion irradiated SA508 reactor pressure vessel steels: Nanoindentation vs in-situ microtensile testing

Influence of Interlayer Forced Air Cooling on Microstructure and Mechanical Properties of Wire Arc Additively Manufactured 304L Austenitic Stainless Steel

“…[ 26 ] Three repetitions on each sample allowed obtaining statistically representative values from such a heterogeneous material. More details on the nanoindentation test are discussed in previous works, [ 27–30 ] where the authors explain how it is possible to calculate the indentation hardness (HI, GPa) and indentation elastic modulus ( E IT, GPa). A representative optical image of the indentation and corresponding load–displacement curves are reported in Figure 2 .…”

On the influence of microstructure on the neutron irradiation response of HIPed SA508 steel for nuclear applications

“…The HIP steel investigated was of alloy type SA508 Grade 3 Class 1, produced as part of an Electrical Power Research Institute (EPRI) development programme and was provided by Rolls-Royce. It is the same steel investigated by Gasparrini et al [26] The resulting alloy composition (of the consolidated material), as determined by chemical analysis methods at Rolls-Royce, is given in Table 1, in addition to the composition of a comparative forged alloy of the same grade used in this project. A result of the HIP process is a steel microstructure different to that produced via conventional forging methods.…”

“…Previous micromechanical testing on the same HIP steel showed that the bainite and ferrite phases had a similar level of hardening when irradiated with He 2+ ions to 0.6dpa. The nanohardness, measured in continuous stiffness measurement mode, of the unirradiated bainite and ferrite phases, was 2.89 ± 0.19GPa and 2.69 ± 0.24GPa respectively, whilst the nanohardness of He 2+ ion irradiated bainite and ferrite was 6.08 ± 0.34GPa and 6.03 ± 0.17GPa respectively [26]. The bainite phase hardened by 3.19 ± 0.39GPa while the ferrite phase hardened by 3.34 ± 0.29GPa as it started as the softer phase.…”

“…Here, the focus lies on the behaviour of SA508 Grade 3 Class 1 HIP steel, encompassing the influence of HIPed microstructure. Usually, RPV steel microstructures are composed of largely of bainite, through HIP manufacturing process a mixed microstructure consisting of islands of bainite and polygonal ferrite was found [26]. Previous micromechanical testing on the same HIP steel showed that the bainite and ferrite phases had a similar level of hardening when irradiated with He 2+ ions to 0.6dpa.…”

Comparing Structure-Property Evolution for Pm-Hip and Forged Alloy 625 Irradiated with Neutrons to 1dpa

“…Previously, only limited investigations into the irradiation response of PM-HIP alloys had been performed. In studies by Carter et al and Gasparrini et al respectively, low-carbon steel SA508 was HIP processed then irradiated with neutrons (155 • C, 0.1 dpa) or He ions (room temperature, 0.6 dpa) [14,15]. Carter and coworkers observed irradiation hardening associated with uniform Ni-Mn-S-P clustering in both the bainite and ferrite phases, whereas Gasparrini and coworkers attributed considerable hardening to bubble/void formation.…”