Cold bulging process for aluminium alloy ring with irregular section

Abstract

Large size aluminium alloy seamless ring with irregular section is usually obtained by hot ring rolling process. Because of residual stress, the ring generally experiences much deflection during subsequent aging and machining. To control this deflection and strengthen the aluminium alloy ring, cold bulging process has to be applied to the ring to homogenize residual stress before aging and machining, and the uniformity of cold deformation is the key problem. The cold bulging process was designed for the forging of the casing ring of aluminium alloy with 5-meter special-shaped section. On this basis, the stress analysis of the cold bulging process was made and the process was engineered. By using Deform-3D to conduct finite element analysis on the ring cold bulging process and stress analysis on different positions of the ring, the deformation characteristics of the ring under the cold bulging process were obtained. The uniformity of the deformation of the ring was achieved by means of the rotation of the disc die when the ring was bulging. The bulging process in the engineering scheme greatly improved the uniformity of the strain in each region of the ring, which provided a reliable theoretical analysis and engineering scheme for the cold bulging process of the ring forgings of aluminium alloy casing with irregular section.