Role of Nickel-141 in mitigating carbon migration and improving impact properties of thermally aged dissimilar welded joint repairs

Three A387 grade 11/AISI 304 dissimilar welded joint (DWJ) repairs were prepared by manual metal arc (MMA) welding with three different composition welding electrodes: Inconel 112, Inconel 182, and Nickel-141 as a buffer layer, followed by Inconel 182 for the first, second, and third repair joints (RJs), respectively. Selected specimens were thermally aged (TA) to induce carbon migration. The microstructure was studied. Line elemental analysis across the fusion line (FL) was carried out using a scanning electron microscope (SEM)/energy-dispersive spectroscopy (EDS). Hardness and Charpy impact test (CIT) were performed. The impact specimens' fractured surfaces were analysed using SEM/EDS. Results showed that Nickel-141 has a significant influence on impeding carbon migration. More importantly, a significant increase in the impact properties has been achieved. Depression in the impact results for the conventional procedures (Inconel 112 and Inconel 182) was found to be partially due to the formation of the carbon-enriched zone (CEZ).