Research on failure control of hydroforming deep drawing for complex surface part

Hydroforming deep drawing is an effective method for manufacturing complex parts which cannot be formed by conventional deep drawing. According to process experiment done on the self-developed hydroforming tester, the fracture, wrinkling and unfittingness failure types in hydroforming deep drawing process of complex surface stainless steel part are investigated. Effect rule of key process parameters including cavity pressure, blank holder force and drawbeads depth on the failures is explored, and cavity pressure and blank holder force loading curve, as well as drawbead depth are optimized. The results show that cavity pressure loading curve should be coordinated with changing trend of sheet noncontact areas. Correspondingly, blank holder force loading path should be performed to match cavity pressure. In addition, appropriate drawbeads must be set up to prevent inner wrinkles on the transition regions of sheet noncontact areas.