Difference in tensile and compressive flow stresses in austenitic stainless steel alloys and its effect on springback behavior

V-bending test was conducted for sixteen different lots of austenitic stainless steel alloys, SUS304. The tensile flow stresses of all alloys were nearly identical to each other in the rolling and transverse directions. We found that the springback angles of all alloys were approximately 20% larger in TD-bending than RD-bending, where RD- and TD-bending refer to the modes of V-bending in which the direction of the bending stress is parallel to the rolling and transverse directions of the sheet, respectively. In order to clarify the cause of the asymmetry of springback behaviour between TD- and RD-bending, in-plane tension and compression tests were carried out for one of the alloys and a tension-compression asymmetry was observed. Consequently, we conclude that the difference in the springback angles between RD- and TD-bending is mainly caused by the significant decrease of the flow stress in the rolling direction due to the Bauschinger effect.