Study On Corrosion Resistance Of Friction Stir Welding Joints Of 5A06 Aluminum Alloy

5A06 aluminum alloy has excellent corrosion resistance, and it is widely used in country's marine equipment. Aluminum alloy joint obtained by traditional fusion welding method is easy to soften, corrosion resistance and quality stability are poor, so the use in advanced equipment such as submarines and mines are limited to some extent, which are required for high corrosion resistance and quality of joints. Friction stir welding is a solid-phase connection technology, and it is a welding method of high quality and efficient, which can improve the quality of aluminum alloy welded joints. Therefore, the research on the process and corrosion resistance of 5A06 aluminum alloy friction stir welding joints have great engineering application value.Appearance and internal defect-free joint has gotten after the adjustment of5A06 aluminum alloy friction stir welding process parameters, and resistance corrosion to seawater polarization curves in each region of the good forming joints are tested, then analysing the forming situation of joints, microstructure,resistant corrosion properties by the testing methods of X-ray flaw detector,metallurgical microscope, SEM and electrochemical workstation.The results show that the variation of tool shape, welding pressure, rotation speed and welding speed had effect on the formbility of joints, in order to eliminate the defects, one or several parameters should be adjusted appropriately,the formbility of joint was the best at the welding parameters of f=35k N,?=300r/min, v=20cm/min; The microstructure and corrosion resistance of friction stir welded joints of different regions were various, the grain size in the nugget zone was the least and the corrosion resistance was the worst, the grain size of the base metal region was the largest and the corrosion resistance was the best, the corrosion resistance of joint was the best at the welding parameters of f=30k N, ?=300r/min, v=20cm/min; Compared with the friction stir welding joint of nugget zone that corrosion resistance was the worst, the pitting potential of TIG welding joint of the weld metal area was more negative, corrosion current density was much higher, so the corrosion resistance of friction stirwelding joint was better than that of the TIG joint.