Corrosion Investigation of Projection Friction Stir Spot Welding of Al 2024 Sheets in Oil and Gas Industry

In order to determine a suitable alternative welding method for the substituation of fusion and resistance welding in oil and gas industry, a new method of projection friction stir spot welding with constant diameter and depth of protrusion was herein used for the welding of 2024 aluminum sheets. by studying the previous research that was done on the friction stir spot welding of this material, the rotational speed of 800rpm was chosen for this purpose. hence, the microstructure along with the corrosion behavior of the projection friction stir spot welding of al2024 joints was investigated as a novel welding technique in oil and gas sector which produced reliable, safe, smooth and keyhole-free joints. the microstructural changes of different welding areas were studied by novel field emission scanning electron microscopy and consequently the hardness profiles of different areas were drawn. the effect of corrosive oil solution containing salts on the welded specimens was studied and various types of pitting and intergranular corrosion were observed in different welding areas. eventually, the accumulation of corrosion products was observed in the stirred area of the weld and the tmaz showed the highest rate of the intergranular corrosion..