Microstructure and Corrosion Behavior Investigation of Al5083-H321 GMAW Weldment in Sea Water

Aluminium 5xxx alloys excellent properties make them suitable for many industrial applications. The corrosion behavior of this alloy family in industrial environments such as sea water is the main focus of many researches. Due to need for joining large segments of this alloys, the effect of single as well as multipass (double and triple pass) gas metal arc welding (GMAW) on microstructure and corrosion behavior of Al5083-H321 alloy was studied. For this purpose, ER5183 filler metal was used. Microstructures were evaluated using optical and scanning electron microscopy (SEM). Corrosion measurements were performed using open circuit potential test, immersion test in 3.5%NaCl solution and polarization tests. Results indicated that the corrosion resistance of the two passes weldment was improved in comparison with the base metal and its icorr and Ecorr were equal to 0.087´10-6 (µA/cm2) and -0.4395 (V), respectively.