Effect of the Filler Metal on the Microstructure, Mechanical Properties, and Corrosion Resistance of Inconel 600 Welded Joints Using Gas Metal Arc Welding

Dissimilar welding of Inconel 600 (IN600) has recently received attention due to its mechanical and corrosion performance and cost reduction during the start‐up of components in the oil/gas industry. For this reason, IN600 plates were welded with gas metal arc welding process using ERNiCrMo‐3 and ER310 filler metals (FMs) and the effects of the heat input, FMs, and shielding gas on the microstructure, mechanical, and corrosion properties were investigated. Optical microscopy revealed that the heat‐affected zone of the welded joints is composed of a grain growth zone, a fine‐grained zone, and an intercritical zone. Due to the lower heat input, when welding with ER310, these zones are narrower, with no significant variations in Vickers hardness (∼280 units). Chemical analysis performed in the scanning electron microscope revealed that Nb, Mo, Cr, and Mn segregate at the interdendritic zones. Tensile tests showed that the yield strength and ultimate tensile strength of the welded joints differed between each other by 12% and 6%, respectively, being higher for the ERNiCrMo‐3 FM. Finally, it was found that the IN600 in the as‐received condition exhibited the highest degree of sensitization and the lowest critical pitting temperature, 7.45% and 56 °C, respectively, in comparison to the welded joints.