Speaker
Shuhei Nogami
(Department of Quantum Science and Energy Engineering)
Description
Tungsten (W) is a primary candidate for fusion reactor divertor because of its high melting point, thermal conductivity and sputtering resistance. To improve its structural reliability, improvement of mechanical properties and suppression of recrystallization of the W materials are necessary. It is well known that the grain refining, work hardening, solid solution strengthening, and dispersion strengthening are the methods for them.
Recently, we have developed various W materials, which were strengthened by a potassium (K) doping for dispersion strengthening and a rhenium (Re) addition for solid solution strengthening. These materials showed advantageous tensile properties and recrystallization temperature in comparison with the conventional pure W plate. Though one of the most important mechanical properties for divertor material is fatigue, limited experimental data on the effect of these strengthening treatments are reported. The objective of this study is to investigate the low cycle fatigue life of these W materials and to clarify the effect of the K-doping and Re addition.
Materials evaluated were pure W plate, K-doped W plate, K-doped W-3%Re plate, and K-doped W rod. Low cycle fatigue tests were carried out at 500ºC in vacuum under axial stroke control. A completely reversed push-pull condition was applied. The total strain range was 0.7%‒1.3%, which was estimated from the stroke range value and mechanical compliance of the testing machine. The effect of the K-doping on the fatigue life was observed in the hot-rolled plate material. The effect of the K-doping and Re addition will be discussed.
Co-authors
Akira Hasegawa
(Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan)
Chiaki Hisaka
(Kobe Material Testing Laboratory Group, Hyogo 675-0155, Japan)
Masaharu Fujiwara
(Kobe Material Testing Laboratory Group, Hyogo 675-0155, Japan)
Shuhei Nogami
(Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan)
Taejoon Kim
(Kobe Material Testing Laboratory Group, Hyogo 675-0155, Japan)
Wenhai Guan
(Department of Quantum Science and Energy Engineering, Tohoku University, Sendai 980-8579, Japan)
