JOPSS - Search Results

Journal Articles

Application of indentation technique to material degradation evaluation in the mercury target vessel for spallation neutron sources

Wakui, Takashi; Saito, Shigeru; Futakawa, Masatoshi

Jikken Rikigaku, 24(4), p.212 - 218, 2024/12

Irradiation damage is one of the main factors determining the lifetime of the mercury target vessel for spallation neutron source in J-PARC. To understand material degradation of the used vessels, it is planned to conduct an evaluation using inverse analyses with indentation tests on the structural materials of the used vessels and numerical experiments. This evaluation technique was applied to two kinds of ion-irradiated materials with different displacement damage doses, in which the irradiation condition was simulated. It could be confirmed that the ultimate strength increased, and the total elongation decreased with increasing irradiation. These trends are like the material degradation behaviors which have been reported by using small specimen's tensile tests.

Journal Articles

Thermal fatigue experiment of screw cooling tube under one-sided heating condition

Ezato, Koichiro; Suzuki, Satoshi; Sato, Kazuyoshi; Akiba, Masato

Journal of Nuclear Materials, 329-333(1), p.820 - 824, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.138

Times Cited Count：7 Percentile：44.42(Materials Science, Multidisciplinary)

This paper presents thermal fatigue experiments of a cooling tube with a helical triangular fin on its inner cooled surface, namely a . The screw thread is directly shaped in a CuCrZr heat sink bar as a cooling channel. Slits with the width of 1.5 mm are machined at the heated side of the heat sink. The thermal fatigue experiments are carried out at 20 and 30 by using an electron beam irradiation facility in JAERI. Water leakages from fatigue cracks, which locate at the slit of the heat sink, occurred at around 4500th and 1400th cycles at 20 and 30 , respectively. These results show good agreement with lifetime predictions using Manson-Coffin's law based on finite element analyses. Fractographic observations reveal that the fatigue cracks start from the outer heated surface at the slit region of the cooling channel and propagate toward its inner surface.

Journal Articles

Post-irradiation tensile and fatigue experiment in JPCA

Kikuchi, Kenji; Saito, Shigeru; Nishino, Yasuharu; Usami, Koji

Proceedings of 6th International Meeting on Nuclear Applications of Accelerator Technology (AccApp '03), p.874 - 880, 2004/00

Specimens irradiated at SINQ were tested by tensile and fatigue. Speciemns were irradiated by 580MeV proton beams under spallation reaction during two years, transported to JAERI and tested at JAERI Hot Cell. Material is JPCA austenitic stainless steel. Strain-to-necking is over 8% at 250 $^{circ}$ C test temperature and are different from APT handbook database. Fatigue test was conducted at low stress regime of high cycle fatigue. The number of cycles to failure is reduced by factors five to ten. These data will help a design of spallation target in JPARC.