[3F01-04] Irradiation Effects

[3F02] Changes in strength of PNC-FMS for wrapper tube of fast reactor by long-term thermal aging

*Koji Fujita¹, Yuta Shizukawa¹, Takashi Tanno¹, Yasuhide Yano¹ (1. Japan Atomic Energy Agency)

Keywords:PNC-FMS, Thermal aging effect, Tensile test, Hardness test

Japan Atomic Energy Agency has been developed 11 Cr martensitic steel PNC-FMS as the candidate material for wrapper tubes of fast reactors. Developing database of property changes by thermally aging is necessary to clarify the irradiation effects from post irradiation experimental data. Tensile tests and hardness measurement of PNC-FMS aged up to 45,000 hours were carried out. Tensile test and hardness test after the thermal aging showed that the strength of specimens aged at 600 °C or higher decreased with aging time. It was shown that the decrease trend was described by linear correlation with Larson-Miller parameter., This means that the strength decrease should have been made by microstructural degradation due to the diffusion-controlled process.