Investigations on Structure–Property Relationships of Inconel 718 and AISI 430 Dissimilar Weldments

In this research work, an attempt has been made to weld nickel-based superalloy, Inconel 718 and ferritic stainless steel, AISI 430, using a gas tungsten arc welding process employing ER2553 and ERNiCrMo-4 fillers. Microstructure studies revealed the formation of an unmixed zone and the presence of tiny Nb-rich phases in the heat-affected zone (HAZ) of Inconel 718; also, grain coarsening was observed at the HAZ of AISI 430. Tensile studies corroborated that the failures occurred at the parent metal of AISI 430 in all the experimental trials. Bend test results revealed that no cracks occurred in either of the weldments reporting for ductility and soundness of the weld joints. This work also articulates the detailed structure–property relationships of these dissimilar weldments using the combined techniques of optical and scanning electron microscopy. The outcomes of the present study will be helpful to the aerospace and nuclear sectors.