Characterisation of Microstructure, Mechanical Properties and Corrosion Behaviour on GTA Welded AISI 310 and Inconel 800

The current work was carried out to characterize the welding of austenitic stainless steel AISI 310 steel to Inconel 800 alloys by Gas Tungsten Arc (GTA) welding using Inconel 600 filler wire. Tensile test shows that failure has occurred in heat affected zone of AISI 310 and its strength was lower as compared to the base metal. In addition the SEM fractographs showed the micro void with some dimple structure which ensures the fracture is ductile in nature. Furthermore the maximum hardness value was found at the weld interface of AISI310 due to the formation of chromium-carbide. The microstructure revealed a considerable change in the grain size and orientation of the Heat Affected Zone (HAZ) in both sides of the weldment than that of the parent metal. Moreover the corrosion test was also carried out in the welded samples both in air and molten salt of Na2SO4 - 50%NaCl at 700 degrees C. The weld zone corroded less readily in the air and molten salt than that of the base metal. It can be concluded that these joints could be used effectively at aggressive environments without compromising the strength.