Numerical and experimental investigation of springback of AISI-301 by hydroforming with membrane diaphragm

AISI-301 steels with their high strength and corrosion resistance, are widely preferred in the aerospace and automotive industries. One of the forming methods for this sheet metals is hydroforming on a form die. In this method, the high pressure transmitted to the part by the diaphragm ensures that the part takes the shape of the die geometry. However, during this forming operation, unpredictable amounts of springback can cause the part to be produced with undesirable deviations. In this study, the springback of AISI-301 sheet material after the hydroforming process was investigated. In this context, specimens with thicknesses of 0.635 mm, 1.016 mm, and 1.27 mm were subjected to hydroforming using a die with bending radius of 2.5 mm, 5 mm, 7.5 mm, and 10 mm and bending angles of 90° and 120° to examine the effects of thickness, bending angle, and bending radius on springback. Additionally, the finite element analyses of the forming process with these variables were conducted using the PAM-STAMP software. Both FEA and experiments have shown that in cases where the sheet thickness to bending radius ratio of AISI-301 stainless steel sheet material reaches 0.1, the amount of springback can reach up to 20 degrees. KEYWORDS: AISI-301 Steel, Hydroforming Process, Springback, Sheet Metal