Varying temperature effects on mechanical properties of vanadium alloys during neutron irradiation

The varying temperature irradiation experiment in the HFIR was carried out in order to investigate the performance of vanadium alloys subject to temperature variation during operation. No significant differences of irradiation hardening between steady 340 °C irradiation and variable 225/340 °C irradiation could be seen in any alloys. In the case of the irradiation at 520 °C, the temperature variation to 360 °C influenced the formation process of voids in the unalloyed and dilute vanadium alloys compared to isothermal irradiation at 520 °C. It is contributed to the change of irradiation hardening behavior between steady irradiation and temperature variable irradiation at 520 °C. It could not be seen any effect of varying irradiation temperature in vanadium alloys containing >1 wt% titanium in this study. It is caused by the insensitivity of formation process of Ti(OCN) precipitates against the effect of irradiation temperature variation.