Doel 3 & Tihange 2 - Some Peer-reviewed Scientific Papers & Reports

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hydrogen contents measured from the fractured specimens also showed the similar trend: unirradiated steel about 5.5 cm 3 H/100 g Fe, steel irradiated at 300-350°C about 3 cm 3 H/100 g Fe and steel irradiated at 100-150°C about 10 cm 3 H/100 g Fe. Consequently, the hydrogen content of the steel is determined by hydrogen traps and the mobility of hydrogen in the steel. The hydrogen embrittlement of a specimen irradiated at a temperature of 300- 350°C may be due to the low diffusion of hydrogen at the bottom of the notch, which makes it possible to generate a local critical hydrogen content in the vicinity of the surface of the specimen. This may be the most important reason for the hydrogen embrittlement of this steel.

Figure 30. The effect of the neutron irradiation temperature on the delayed fracture of 15Kh3MFA steel during continuous hydrogen charging (current density 0.6 A / dm 2 ): unirradiated specimen (o), at temperature of 300-350°C ( ) and 100-150°C ( ) irradiated specimen (Alekseenko et al. 1977).