Fatigue Life Evaluation of TIG-weld of Reduced Activation Ferritic/Martensitic Steel F82H by Small Specimen Test Technique

Evaluation of the low cycle fatigue life by the small specimen test technique (SSTT) and some other properties (metallographical structure and Vickers hardness) for the TIG (tungsten inert gas) weld of F82H IEA-heat were carried out. The TIG-weld was distinguished into seven regions with different metallographical structure and hardness, which were the base metal (BM) region (region with almost no thermal history in the weld), three regions of the heat affected zone (HAZ), and the three regions of the weld metal. There seemed to be no significant correlation between Vickers hardness and average prior austenitic grain size of the individual regions of the TIG-weld. The region with larger prior austenitic grain than the base metal showed similar fatigue life to the BM and the raw material (material used for the TIG-weld). While, the region with relatively small prior austenitic grain showed longer fatigue life than it.