The influence of number of welding passes on the corrosion behavior of the Gas Metal Arc weldments of aluminium 5083 alloy was investigated. For this purpose, the samples with single, double and triple passes were fabricated using ER5183 as filler metal. The microstructure of different welds was investigated byoptical microscopy and scanning electron microscopy. Also, the hardness profiles were determined using microhardness tests. The corrosion behavior of the base metal and welds was investigated by conducting immersion test, Tafel polarization and slow strain rate test (SSRT) in 3.5% NaCl solution. The result indicated that the welds including a dendritic structure. The dendrite arm spacing increased by increasing the number of passes. Based on the immersion and Tafel polarization tests, the double passes sample revealed superior corrosion behavior among other welds. SSRT results showed that the base alloy had the best SCC behavior by ultimate tensile strength of about 366.5 MPa. Elongation and area reduction measurements after SSRT indicated that the base alloy exhibited more ductile behavior in 3.5% NaCl solution in comparison with the welds. Furthermore, the SEM studies of the fracture surfaces of different samples showed the dimple mode which was the characterization of ductile fracture. However, some semi-cleavage were observed in the fracture surfaces of the welds.
