The quality analysis of multi-step forming the higher D/t cylinder

Abstract

In order to solve the problem of large springback in higher D/t cylinder stamping, the method of hydroforming following drawing is adopted in this paper. It can reduce the residual stress of the cylinder after heat treatment. The effects of the stretching height, hydraulic pressure and blank holder force on the cylinder quality are investigated using the finite element software dynaform, and the optimal process parameters are obtained. In case that the stretching height, blank holder force and hydraulic pressure are relatively 55 mm, 12,5 MPa and 20 KN, the rate of wall thickness variation and springback are obviously reduced. The research results lay a theoretical foundation for improving the plastic deformation of thin-walled cylinder.

Keywords

• plastic deformation
• hydroforming
• sheet
• the cylinder
• stretching height