Investigation of structure and properties of the welded joint obtained by friction stir welding of 1580 alloy hot-rolled sheets

The weldability of hot-rolled sheets of alloy 1580 by friction stir welding was investigated. The test blanks were cutfrom 6.0 mm thick sheets, which were produced under industrial conditions by hot rolling of large-size ingots with dimensions of 300×1445×2200 mm at the “SGP Kvarto 2800” mill. Cards of 210×297 mm size were cut from the sheets and then roasted under two regimes: at 300 °C for three hours and at 350 °C for three hours. The work solved the problems of determining the mechanical properties of welded samples by tensile tests, investigating the structure of the weld by metallographic and electron microscopic methods, assessing the quality of the weld by radiographic analysis and technological tests for static bending. It has been established that the use of the friction stir welding method for joining 1580 alloy sheets allows to obtain high quality of the welded seam. Mechanical tests have shown that the strength of welded joints obtained by the FSW method is almost at the level of the base metal strength and does not depend on the localization of the fracture point. The samples after welding withstood bending tests without cracks along the entire length of the weld, both by bending at an angle of 150° with a mandrel, and after continued testing by static bending in a vise to parallelism of the sides. The work was carried out by the laboratory of low-carbon metallurgy and power engineering within the framework of the state assignment of “Siberian Federal University” of the organization-participant of REC “Yenisei Siberia” within the framework of the national project “Science and Universities”, project number FSRZ-2024-0004.