Effects of Preform on Thickness Distribution of Hydroformed Y-Shaped Tube

摘要

Hydroforming processes of a Y-shaped stainless steel tube with d/t (ratio of diameter to thickness) of 183 is presented. FEM simulations were carried out for analyzing the stress states and thickness distribution in the workpieces during hydroforming of the Y-shaped tube. A two-step process with preform procedure is presented to improve the stress states in the protrusion and to avoid the severe thinning at the top of the protrusion. Through the two-step hydroforming, the wrinkling and cracking defects were all avoided and sound components were produced.