Fusion Science and Technology / Volume 47 / Number 4 / May 2005 / Pages 856-860
Technical Paper / Fusion Energy - Fusion Materials
The dependence of ductile-brittle transition temperature (DBTT) on tempering time and temperature was examined for a martensitic steel F82H irradiated at 150 and 250°C to a neutron dose of 1.9 dpa in the JMTR. The heat treatment was performed at 750 and 780°C for 0.5 h after the normalizing at 1040°C for 0.5 h. The tempering time at 750°C was varied from 0.5 to 10 h. 1/3CVN specimens were used in this study, and the absorbed energies in the impact tests were measured as a function of temperature. DBTT of F82H steels irradiated at 250°C to 1.9 dpa was ranged from -23 to 25°C, and DBTT of F82H steels irradiated at 150°C to 1.9 dpa was ranged from 0 to 15°C. DBTT of F82H steels irradiated at 250°C depended strongly on temperature and time of tempering, and it tended to decrease with increasing yield stress. The effect of tempering conditions on DBTT was smaller in the specimens irradiated at 150°C. DBTT due to irradiation in the F82H steels irradiated at 250°C tended to decrease with increasing time and temperature of tempering.