Intergranular corrosion behavior of Inconel 625 deposited by CMT/GTAW

The intergranular corrosion (IGC) behavior of Inconel 625 cladding layer deposited by cold metal transfer (CMT) at different positions from the substrate has been studied. Compared with the Gas tungsten arc welding (GTAW) welds, the IGC resistance of the CMT-welds is significantly improved by about 73.7%, which is attributed to the optimized grain boundary structure and lower Fe content in the CMT-welds. Furthermore, as the overlay approaches the X65 substrate, the IGC resistance decreases. This is due to the combined effect of the smaller grain size and high Fe content of the overlay close to the substrate.