Process Parameters Optimization of One-Step Spin Forming of Top Cover with Center Flanged Hole

To assist the low-cost manufacturing of tanks, a one-step method of marginal-restraint mandrel-free spin forming is therefore proposed in this study for the forming of top covers with flanged holes. With the finite element simulation analysis, three different forming strategies are discussed, and the best spinning process is identified. The proposed forming strategies involve preforming the flanged surface first and then preforming the spherical and flanged surfaces in a subsequent trajectory and is proved to have better forming accuracy. Furthermore, the forming quality of the spun parts is improved and optimized by employing more passes, smaller feed ratios, and larger roller fillet radii. It was experimentally verified that the marginal-restraint mandrel-free spinning one-step method with five passes, a feed ratio of 1 mm/r, and a roller fillet radius of 60 mm for the cylindrical roller can achieve accurate forming of a top cover with a center flange hole.