Strength Evaluation of a Single Layer Passed TIG Weld Joint in Advanced Reduced Activation Alloy by Small Punch Test for HCCR TBM in ITER

Korea has developed a helium-cooled ceramic reflector (HCCR) test blanket module (TBM) for ITER, and Korean reduced activation ferritic martensitic (RAFM) steel, which is named ARAA (advanced reduced activation alloy), has also been developed for a structural material of the KO HCCR TBM. To evaluate the welding fabrication technology in the TBM, one case of TIG welding conditions was selected based on the previous work by Yoon et al. (2013), and a single pass with one side weld procedure through a thickness in TIG weld was carried out using ARAA, Batch 2 (F206). The microstructure was observed in the base, heat affected zone (HAZ), and weld region, and the micro-hardness was measured from the base to the weld region. In addition, a small punch (SP) test considering the base metal and HAZ region was carried out at room and high (550°C) temperatures. The empirical mechanical properties of the HAZ were estimated based on the correlation between the tensile and SP test in the base metal, and the fracture morphology was observed after the SP test.