CORROSION AND MECHANICAL DURABILITY OF WELDED JOINTS OF ALUMINUM ALLOY V1341, PRODUCED BY ARGON-ARC WELDING BY FREE AND CONSTRICTED ARC

摘要

The paper presents the results of studies of corrosion and mechanical resistance of welded joints of V1341 alloy of 1.2 mm thickness, depending on the technology of manual argon arc welding with free and constricted arc. The strength coefficient of welded joints is 0.79 and 0.8, respectively. Potentiometric measurements showed an electrochemical heterogeneity between the base metal and welded joints obtained by free and constricted arc; with a potential difference equal to 100 mV and 86 mV, respectively. More positive potential is inherent to the region with a smaller weld area, which is safe for operation. Accelerated corrosion tests have determined that the shape of the arc column in manual welding does not affect the resistance of welded joints against exfoliating corrosion and against corrosion-mechanical breaking under conditions of constant deformation. The level of resistance of the base metal against exfoliating corrosion of the joints, produced by both types of arc welding technology, was estimated by number 2-3. The fracture time of specimens of the joints produced by free arc welding, decreased on average to 20 days compared to the base metal (73 days). Similar results were obtained for joints welded by a constricted arc. At the same time, it was found that using of a constricted arc for welding causes a lowering of the resistance of the joints against intergranular corrosion. The maximum breaking depth of grain boundaries for joints produced by a free arc is 0.350 mm, and for the joints made by a constricted arc it is 0.460 mm.