in this present study microstructure and mechanical properties ofAISI 316 In the present study, microstructure and mechanical properties of AISI 316 austenitic stainless steel(ASS)/AISI 405 Ferritic stainless steel (FSS) dissimilar joints were investigated. Dissimilar joints were fabricated by Gas Tungsten Arc Welding (GTAW) using different filler metals of ER309, ER316, ER347 and ERNiCr3. The microstructures were studied by optical microscopy, scanning electron microscopy and X-ray diffraction analysis. The mechanical properties of the joints were investigated using impact, tensile, hardness and shear punch tests. Furthermore, the corrosion behavior of the joints was evaluated using cyclic polarization and immersion tests in a 0.1 M NaCl solution and 0.1 M H 2 SO 4 . Results showed that different microstructures were formed with different amounts of delta ferrite. The formation of acicular delta-ferrite phase was encouraged by increasing the ferrite stabilizing elements in the welds. Also, scanning electron microscopy analysis indicated that the use of 347 and 316 filler metals significantly improved the mechanical properties of the welds due to formation of a finer structure containing titanium, niobium and molybdenum elements. The results of the tensile tests showed that all the joints failed from a weaker region which was ferritic base metal. The impact tests indicated that the impact strength of the weld fabricated by 347 filler metal was the highest among different welds. The shear punch tests showed the highest yield and shear strength for the weld formed by 347 filler metal. The corrosion experiments showed that the corrosion resistance of the welds was significantly dependent to the filler metals. Key words : Austenitic stainless steel, ferritic stainless steel, shear punch test, scanning electron microscopy, corrosion resistance. .
