The cold-rolled thin-wall pipe of 5A02 alloy was homogenizing annealed using a resistance furnace. Optical microscope, hardness testing machine and universal testing machine were used to investigate the effect of homogenizing annealing on the microstructure and properties of 5A02 alloy pipe. It is found that there still exists a certain amount of fibrous structure in 5A02 alloy which annealed at lower temperatures for 60 min. However, with the annealing temperature increasing to 410℃ and holding for 30 min, the microstructure is composed of fine recrystallized grains with all the fibrous structure has completely disappeared. The strength and hardness of the annealed 5A02 alloy pipe decrease gradually with the increasing annealing temperature and holding time, while the elongation is gradually increased. It is also found that there is little change in the properties of 5A02 alloy pipe which annealed more than 30 min. At lower homogenizing annealing temperature, the toughness fracture of the alloy is the main features of the fracture surface, in which there still exists a small amount of shear deformation feature. However, the alloy displays a large mount of toughness fractures and nearly no shear deformation features with the increasing annealing temperature. Finally, the homogenizing annealing temperature is determined to be at 410430℃ for 3060 min, after which the mechanical properties are satisfied with the application requirements.
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