Investigation on the weakest zone in toughness of 9Cr/NiCrMoV dissimilar welded joint and its enhancement

The impact toughness and related microstructure of the dissimilar 9Cr/NiCrMoV welded joint fabricated by narrow-gap submerged arc welding were systematically investigated in the paper. Results indicated that the fracture appearance transition temperature (50% FATT) for weld metal was −11 °C, while low and scattered absorbed energies determined by different crack growth paths for the heat affected zone of 9Cr were gained which could not satisfy...