Low Cycle Fatigue properties at elevated temperature on TIG

Since the Test Blanket Module (TBM) will be operated at the wide range of elevated temperatures under cyclic thermal loading condition, thermal fatigue is one of the key life-limiting factors. The primary candidate for the structural material of TBM is the Reduced Activation Ferritic/Martensitic (RAFM) steel. A TIG welding of RAFM steel is one of key technologies for the fabrication of the TBM. Especially, the integrity of TIG welded RAFM steel under long-term thermal load condition should be guaranteed considering the TBM operation in ITER. In the previous study, a TIG welding condition for the RAFM steel was derived and main results were published. In this study, Low Cycle Fatigue (LCF) test was performed on the base metal and TIG weldment. To confirm the reliability of the TIG welded RAFM steel, the effects of Heat Affected Zone (HAZ) on LCF properties at room temperature and 550 °C were investigated.